diff --git a/demo/package-lock.json b/demo/package-lock.json
index 070e850..4e22ae6 100644
--- a/demo/package-lock.json
+++ b/demo/package-lock.json
@@ -2787,7 +2787,8 @@
             },
             "ansi-regex": {
               "version": "2.1.1",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "aproba": {
               "version": "1.2.0",
@@ -2805,11 +2806,13 @@
             },
             "balanced-match": {
               "version": "1.0.0",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "brace-expansion": {
               "version": "1.1.11",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "balanced-match": "^1.0.0",
                 "concat-map": "0.0.1"
@@ -2822,15 +2825,18 @@
             },
             "code-point-at": {
               "version": "1.1.0",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "concat-map": {
               "version": "0.0.1",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "console-control-strings": {
               "version": "1.1.0",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "core-util-is": {
               "version": "1.0.2",
@@ -2933,7 +2939,8 @@
             },
             "inherits": {
               "version": "2.0.3",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "ini": {
               "version": "1.3.5",
@@ -2943,6 +2950,7 @@
             "is-fullwidth-code-point": {
               "version": "1.0.0",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "number-is-nan": "^1.0.0"
               }
@@ -2955,17 +2963,20 @@
             "minimatch": {
               "version": "3.0.4",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "brace-expansion": "^1.1.7"
               }
             },
             "minimist": {
               "version": "0.0.8",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "minipass": {
               "version": "2.3.5",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "safe-buffer": "^5.1.2",
                 "yallist": "^3.0.0"
@@ -2982,6 +2993,7 @@
             "mkdirp": {
               "version": "0.5.1",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "minimist": "0.0.8"
               }
@@ -3054,7 +3066,8 @@
             },
             "number-is-nan": {
               "version": "1.0.1",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "object-assign": {
               "version": "4.1.1",
@@ -3064,6 +3077,7 @@
             "once": {
               "version": "1.4.0",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "wrappy": "1"
               }
@@ -3139,7 +3153,8 @@
             },
             "safe-buffer": {
               "version": "5.1.2",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "safer-buffer": {
               "version": "2.1.2",
@@ -3169,6 +3184,7 @@
             "string-width": {
               "version": "1.0.2",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "code-point-at": "^1.0.0",
                 "is-fullwidth-code-point": "^1.0.0",
@@ -3186,6 +3202,7 @@
             "strip-ansi": {
               "version": "3.0.1",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "ansi-regex": "^2.0.0"
               }
@@ -3224,11 +3241,13 @@
             },
             "wrappy": {
               "version": "1.0.2",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "yallist": {
               "version": "3.0.3",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             }
           }
         },
@@ -4287,17 +4306,24 @@
       "integrity": "sha512-aCTPIfY1Jvuam5b6vuWRjt1F8i4kY7zX0Qtpu5SNd6l1zjuxU9fDNpbM4o6+oJsra+TMD2o7D20GnkSIgpTr9w=="
     },
     "elliptic": {
-      "version": "6.5.0",
-      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.0.tgz",
-      "integrity": "sha512-eFOJTMyCYb7xtE/caJ6JJu+bhi67WCYNbkGSknu20pmM8Ke/bqOfdnZWxyoGN26JgfxTbXrsCkEw4KheCT/KGg==",
+      "version": "6.5.4",
+      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.4.tgz",
+      "integrity": "sha512-iLhC6ULemrljPZb+QutR5TQGB+pdW6KGD5RSegS+8sorOZT+rdQFbsQFJgvN3eRqNALqJer4oQ16YvJHlU8hzQ==",
       "requires": {
-        "bn.js": "^4.4.0",
-        "brorand": "^1.0.1",
+        "bn.js": "^4.11.9",
+        "brorand": "^1.1.0",
         "hash.js": "^1.0.0",
-        "hmac-drbg": "^1.0.0",
-        "inherits": "^2.0.1",
-        "minimalistic-assert": "^1.0.0",
-        "minimalistic-crypto-utils": "^1.0.0"
+        "hmac-drbg": "^1.0.1",
+        "inherits": "^2.0.4",
+        "minimalistic-assert": "^1.0.1",
+        "minimalistic-crypto-utils": "^1.0.1"
+      },
+      "dependencies": {
+        "bn.js": {
+          "version": "4.12.0",
+          "resolved": "https://registry.npmjs.org/bn.js/-/bn.js-4.12.0.tgz",
+          "integrity": "sha512-c98Bf3tPniI+scsdk237ku1Dc3ujXQTSgyiPUDEOe7tRkhrqridvh8klBv0HCEso1OLOYcHuCv/cS6DNxKH+ZA=="
+        }
       }
     },
     "emoji-regex": {
@@ -6620,7 +6646,8 @@
             },
             "ansi-regex": {
               "version": "2.1.1",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "aproba": {
               "version": "1.2.0",
@@ -6638,11 +6665,13 @@
             },
             "balanced-match": {
               "version": "1.0.0",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "brace-expansion": {
               "version": "1.1.11",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "balanced-match": "^1.0.0",
                 "concat-map": "0.0.1"
@@ -6655,15 +6684,18 @@
             },
             "code-point-at": {
               "version": "1.1.0",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "concat-map": {
               "version": "0.0.1",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "console-control-strings": {
               "version": "1.1.0",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "core-util-is": {
               "version": "1.0.2",
@@ -6766,7 +6798,8 @@
             },
             "inherits": {
               "version": "2.0.3",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "ini": {
               "version": "1.3.5",
@@ -6776,6 +6809,7 @@
             "is-fullwidth-code-point": {
               "version": "1.0.0",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "number-is-nan": "^1.0.0"
               }
@@ -6788,17 +6822,20 @@
             "minimatch": {
               "version": "3.0.4",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "brace-expansion": "^1.1.7"
               }
             },
             "minimist": {
               "version": "0.0.8",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "minipass": {
               "version": "2.3.5",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "safe-buffer": "^5.1.2",
                 "yallist": "^3.0.0"
@@ -6815,6 +6852,7 @@
             "mkdirp": {
               "version": "0.5.1",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "minimist": "0.0.8"
               }
@@ -6887,7 +6925,8 @@
             },
             "number-is-nan": {
               "version": "1.0.1",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "object-assign": {
               "version": "4.1.1",
@@ -6897,6 +6936,7 @@
             "once": {
               "version": "1.4.0",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "wrappy": "1"
               }
@@ -6972,7 +7012,8 @@
             },
             "safe-buffer": {
               "version": "5.1.2",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "safer-buffer": {
               "version": "2.1.2",
@@ -7002,6 +7043,7 @@
             "string-width": {
               "version": "1.0.2",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "code-point-at": "^1.0.0",
                 "is-fullwidth-code-point": "^1.0.0",
@@ -7019,6 +7061,7 @@
             "strip-ansi": {
               "version": "3.0.1",
               "bundled": true,
+              "optional": true,
               "requires": {
                 "ansi-regex": "^2.0.0"
               }
@@ -7057,11 +7100,13 @@
             },
             "wrappy": {
               "version": "1.0.2",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             },
             "yallist": {
               "version": "3.0.3",
-              "bundled": true
+              "bundled": true,
+              "optional": true
             }
           }
         }