Bump eslint from 3.19.0 to 4.18.2

Bumps [eslint](https://github.com/eslint/eslint) from 3.19.0 to 4.18.2.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](eslint/eslint@v3.19.0...v4.18.2)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -31,7 +31,7 @@
   "devDependencies": {
     "chai": "^3.5.0",
     "devtools-protocol": "^0.0.739646",
-    "eslint": "^3.12.0",
+    "eslint": "^4.18.2",
     "eslint-config-google": "^0.7.1",
     "gulp": "^3.9.1",
     "mocha": "^3.2.0",