chore(package): update eslint to version 6.5.1

Closes #93

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
   "homepage": "https://github.com/elliotttf/jsonapi-validator#readme",
   "devDependencies": {
     "coveralls": "^2.11.9",
-    "eslint": "^4.4.1",
+    "eslint": "^6.5.1",
     "eslint-config-airbnb-base": "^11.0.1",
     "eslint-plugin-import": "^2.7.0",
     "ghooks": "^2.0.0",