chore(package): update eslint to version 6.7.1

Closes #36

Author: greenkeeper[bot]

package.json

@@ -74,7 +74,7 @@
     "codecov": "^3.0.0",
     "commitplease": "^3.1.0",
     "cz-conventional-changelog": "^2.0.0",
-    "eslint": "^5.0.0",
+    "eslint": "^6.7.1",
     "husky": "^1.0.0",
     "mocha": "^6.0.0",
     "nyc": "^14.0.0",