fix(package): update eslint to version 6.2.2

Closes #5

Author: greenkeeper[bot]

package.json

@@ -11,7 +11,7 @@
   ],
   "dependencies": {
     "ajv": "^5.2.2",
-    "eslint": "^3.19.0",
+    "eslint": "^6.2.2",
     "eslint-config-airbnb-base": "^11.2.0",
     "eslint-config-standard": "^10.2.1",
     "eslint-plugin-import": "^2.7.0",