chore(deps): update dependency eslint to v4

Author: renovate[bot]

package.json

@@ -37,7 +37,7 @@
     "babel-register": "6.26.0",
     "conventional-changelog-cli": "1.3.22",
     "doctoc": "1.4.0",
-    "eslint": "3.19.0",
+    "eslint": "4.19.1",
     "eslint-config-algolia": "6.0.1",
     "eslint-import-resolver-webpack": "0.13.10",
     "eslint-plugin-import": "2.22.0",