diff --git a/example/package-lock.json b/example/package-lock.json
index 1b4a5fe..9f3c58a 100644
--- a/example/package-lock.json
+++ b/example/package-lock.json
@@ -94,15 +94,23 @@
       "dev": true
     },
     "ajv": {
-      "version": "6.6.1",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.6.1.tgz",
-      "integrity": "sha512-ZoJjft5B+EJBjUyu9C9Hc0OZyPZSSlOF+plzouTrg6UlA8f+e/n8NIgBFG/9tppJtpPWfthHakK7juJdNDODww==",
+      "version": "6.12.6",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
       "dev": true,
       "requires": {
-        "fast-deep-equal": "^2.0.1",
+        "fast-deep-equal": "^3.1.1",
         "fast-json-stable-stringify": "^2.0.0",
         "json-schema-traverse": "^0.4.1",
         "uri-js": "^4.2.2"
+      },
+      "dependencies": {
+        "fast-deep-equal": {
+          "version": "3.1.3",
+          "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
+          "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
+          "dev": true
+        }
       }
     },
     "ajv-errors": {
@@ -598,7 +606,7 @@
         },
         "util": {
           "version": "0.10.3",
-          "resolved": "http://registry.npmjs.org/util/-/util-0.10.3.tgz",
+          "resolved": "https://registry.npmjs.org/util/-/util-0.10.3.tgz",
           "integrity": "sha1-evsa/lCAUkZInj23/g7TeTNqwPk=",
           "dev": true,
           "requires": {
@@ -709,7 +717,7 @@
         },
         "chalk": {
           "version": "1.1.3",
-          "resolved": "http://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
           "integrity": "sha1-qBFcVeSnAv5NFQq9OHKCKn4J/Jg=",
           "dev": true,
           "requires": {
@@ -2921,7 +2929,7 @@
       "dependencies": {
         "domelementtype": {
           "version": "1.1.3",
-          "resolved": "http://registry.npmjs.org/domelementtype/-/domelementtype-1.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/domelementtype/-/domelementtype-1.1.3.tgz",
           "integrity": "sha1-vSh3PiZCiBrsUVRJJCmcXNgiGFs=",
           "dev": true
         }
@@ -3362,7 +3370,7 @@
       "dependencies": {
         "doctrine": {
           "version": "1.5.0",
-          "resolved": "http://registry.npmjs.org/doctrine/-/doctrine-1.5.0.tgz",
+          "resolved": "https://registry.npmjs.org/doctrine/-/doctrine-1.5.0.tgz",
           "integrity": "sha1-N53Ocw9hZvds76TmcHoVmwLFpvo=",
           "dev": true,
           "requires": {
@@ -3663,7 +3671,7 @@
       "dependencies": {
         "array-flatten": {
           "version": "1.1.1",
-          "resolved": "http://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
+          "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
           "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI=",
           "dev": true
         }
@@ -3722,12 +3730,6 @@
       "integrity": "sha1-lpGEQOMEGnpBT4xS48V06zw+HgU=",
       "dev": true
     },
-    "fast-deep-equal": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-2.0.1.tgz",
-      "integrity": "sha1-ewUhjd+WZ79/Nwv3/bLLFf3Qqkk=",
-      "dev": true
-    },
     "fast-json-stable-stringify": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
@@ -3958,7 +3960,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -3979,12 +3982,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -3999,17 +4004,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -4126,7 +4134,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -4138,6 +4147,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -4152,6 +4162,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -4159,12 +4170,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.2.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -4183,6 +4196,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -4263,7 +4277,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -4275,6 +4290,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -4360,7 +4376,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -4396,6 +4413,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -4415,6 +4433,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -4458,12 +4477,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
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@@ -7183,7 +7204,7 @@
     },
     "pify": {
       "version": "2.3.0",
-      "resolved": "http://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
+      "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
       "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
       "dev": true
     },
@@ -7241,7 +7262,7 @@
       "dependencies": {
         "async": {
           "version": "1.5.2",
-          "resolved": "http://registry.npmjs.org/async/-/async-1.5.2.tgz",
+          "resolved": "https://registry.npmjs.org/async/-/async-1.5.2.tgz",
           "integrity": "sha1-7GphrlZIDAw8skHJVhjiCJL5Zyo=",
           "dev": true
         }
@@ -7563,7 +7584,7 @@
     },
     "readable-stream": {
       "version": "2.3.6",
-      "resolved": "http://registry.npmjs.org/readable-stream/-/readable-stream-2.3.6.tgz",
+      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.3.6.tgz",
       "integrity": "sha512-tQtKA9WIAhBF3+VLAseyMqZeBjW0AHJoxOtYqSUZNJxauErmLbVm2FW1y+J/YA9dUrAC39ITejlZWhVIwawkKw==",
       "dev": true,
       "requires": {
@@ -9127,7 +9148,7 @@
     },
     "strip-ansi": {
       "version": "3.0.1",
-      "resolved": "http://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
+      "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
       "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
       "dev": true,
       "requires": {
@@ -9474,7 +9495,7 @@
         },
         "yargs": {
           "version": "3.10.0",
-          "resolved": "http://registry.npmjs.org/yargs/-/yargs-3.10.0.tgz",
+          "resolved": "https://registry.npmjs.org/yargs/-/yargs-3.10.0.tgz",
           "integrity": "sha1-9+572FfdfB0tOMDnTvvWgdFDH9E=",
           "dev": true,
           "requires": {
@@ -9973,7 +9994,7 @@
         },
         "async": {
           "version": "1.5.2",
-          "resolved": "http://registry.npmjs.org/async/-/async-1.5.2.tgz",
+          "resolved": "https://registry.npmjs.org/async/-/async-1.5.2.tgz",
           "integrity": "sha1-7GphrlZIDAw8skHJVhjiCJL5Zyo=",
           "dev": true
         },
@@ -10031,7 +10052,7 @@
         },
         "crypto-browserify": {
           "version": "3.3.0",
-          "resolved": "http://registry.npmjs.org/crypto-browserify/-/crypto-browserify-3.3.0.tgz",
+          "resolved": "https://registry.npmjs.org/crypto-browserify/-/crypto-browserify-3.3.0.tgz",
           "integrity": "sha1-ufx1u0oO1h3PHNXa6W6zDJw+UGw=",
           "dev": true,
           "requires": {
@@ -10127,7 +10148,7 @@
         },
         "pako": {
           "version": "0.2.9",
-          "resolved": "http://registry.npmjs.org/pako/-/pako-0.2.9.tgz",
+          "resolved": "https://registry.npmjs.org/pako/-/pako-0.2.9.tgz",
           "integrity": "sha1-8/dSL073gjSNqBYbrZ7P1Rv4OnU=",
           "dev": true
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@@ -10139,7 +10160,7 @@
         },
         "ripemd160": {
           "version": "0.2.0",
-          "resolved": "http://registry.npmjs.org/ripemd160/-/ripemd160-0.2.0.tgz",
+          "resolved": "https://registry.npmjs.org/ripemd160/-/ripemd160-0.2.0.tgz",
           "integrity": "sha1-K/GYveFnys+lHAqSjoS2i74XH84=",
           "dev": true
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@@ -10172,13 +10193,13 @@
         },
         "tapable": {
           "version": "0.1.10",
-          "resolved": "http://registry.npmjs.org/tapable/-/tapable-0.1.10.tgz",
+          "resolved": "https://registry.npmjs.org/tapable/-/tapable-0.1.10.tgz",
           "integrity": "sha1-KcNXB8K3DlDQdIK10gLo7URtr9Q=",
           "dev": true
         },
         "uglify-js": {
           "version": "2.7.5",
-          "resolved": "http://registry.npmjs.org/uglify-js/-/uglify-js-2.7.5.tgz",
+          "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-2.7.5.tgz",
           "integrity": "sha1-RhLAx7qu4rp8SH3kkErhIgefLKg=",
           "dev": true,
           "requires": {
@@ -10190,7 +10211,7 @@
           "dependencies": {
             "async": {
               "version": "0.2.10",
-              "resolved": "http://registry.npmjs.org/async/-/async-0.2.10.tgz",
+              "resolved": "https://registry.npmjs.org/async/-/async-0.2.10.tgz",
               "integrity": "sha1-trvgsGdLnXGXCMo43owjfLUmw9E=",
               "dev": true
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@@ -10209,7 +10230,7 @@
           "dependencies": {
             "async": {
               "version": "0.9.2",
-              "resolved": "http://registry.npmjs.org/async/-/async-0.9.2.tgz",
+              "resolved": "https://registry.npmjs.org/async/-/async-0.9.2.tgz",
               "integrity": "sha1-rqdNXmHB+JlhO/ZL2mbUx48v0X0=",
               "dev": true
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@@ -10240,7 +10261,7 @@
           "dependencies": {
             "acorn": {
               "version": "3.3.0",
-              "resolved": "http://registry.npmjs.org/acorn/-/acorn-3.3.0.tgz",
+              "resolved": "https://registry.npmjs.org/acorn/-/acorn-3.3.0.tgz",
               "integrity": "sha1-ReN/s56No/JbruP/U2niu18iAXo=",
               "dev": true
             },
@@ -10266,7 +10287,7 @@
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         "yargs": {
           "version": "3.10.0",
-          "resolved": "http://registry.npmjs.org/yargs/-/yargs-3.10.0.tgz",
+          "resolved": "https://registry.npmjs.org/yargs/-/yargs-3.10.0.tgz",
           "integrity": "sha1-9+572FfdfB0tOMDnTvvWgdFDH9E=",
           "dev": true,
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@@ -10296,7 +10317,7 @@
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         "source-map": {
           "version": "0.4.4",
-          "resolved": "http://registry.npmjs.org/source-map/-/source-map-0.4.4.tgz",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.4.4.tgz",
           "integrity": "sha1-66T12pwNyZneaAMti092FzZSA2s=",
           "dev": true,
           "requires": {
@@ -10404,7 +10425,7 @@
         },
         "os-locale": {
           "version": "1.4.0",
-          "resolved": "http://registry.npmjs.org/os-locale/-/os-locale-1.4.0.tgz",
+          "resolved": "https://registry.npmjs.org/os-locale/-/os-locale-1.4.0.tgz",
           "integrity": "sha1-IPnxeuKe00XoveWDsT0gCYA8FNk=",
           "dev": true,
           "requires": {
@@ -10430,7 +10451,7 @@
         },
         "yargs": {
           "version": "6.6.0",
-          "resolved": "http://registry.npmjs.org/yargs/-/yargs-6.6.0.tgz",
+          "resolved": "https://registry.npmjs.org/yargs/-/yargs-6.6.0.tgz",
           "integrity": "sha1-eC7CHvQDNF+DCoCMo9UTr1YGUgg=",
           "dev": true,
           "requires": {
@@ -10451,7 +10472,7 @@
         },
         "yargs-parser": {
           "version": "4.2.1",
-          "resolved": "http://registry.npmjs.org/yargs-parser/-/yargs-parser-4.2.1.tgz",
+          "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-4.2.1.tgz",
           "integrity": "sha1-KczqwNxPA8bIe0qfIX3RjJ90hxw=",
           "dev": true,
           "requires": {
@@ -10632,7 +10653,7 @@
     },
     "yargs": {
       "version": "11.1.0",
-      "resolved": "http://registry.npmjs.org/yargs/-/yargs-11.1.0.tgz",
+      "resolved": "https://registry.npmjs.org/yargs/-/yargs-11.1.0.tgz",
       "integrity": "sha512-NwW69J42EsCSanF8kyn5upxvjp5ds+t3+udGBeTbFnERA+lF541DDpMawzo4z6W/QrzNM18D+BPMiOBibnFV5A==",
       "dev": true,
       "requires": {