Bump eslint from 3.13.1 to 4.18.2

Bumps [eslint](https://github.com/eslint/eslint) from 3.13.1 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@v3.13.1...v4.18.2)

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

package.json

@@ -55,7 +55,7 @@
     "babel-register": "6.18.0",
     "coveralls": "2.11.15",
     "cross-env": "3.1.4",
-    "eslint": "3.13.1",
+    "eslint": "4.18.2",
     "eslint-config-standard": "6.2.1",
     "eslint-plugin-ava": "4.0.1",
     "eslint-plugin-promise": "3.4.0",