chore(package): update eslint to version 6.5.1

Closes #43

Author: greenkeeper[bot]

package.json

@@ -31,7 +31,7 @@
   },
   "devDependencies": {
     "coveralls": "^3.0.2",
-    "eslint": "^5.14.1",
+    "eslint": "^6.5.1",
     "eslint-config-mr": "^1.1.0",
     "expect.js": "^0.3.1",
     "express": "^4.16.4",