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>

Author: dependabot[bot]

package.json

@@ -31,7 +31,7 @@
     "chai": "^3.5.0",
     "chai-as-promised": "^6.0.0",
     "ember-cli": "^3.18.0",
-    "eslint": "^3.18.0",
+    "eslint": "^4.18.2",
     "github": "^0.2.4",
     "glob": "^7.1.1",
     "mocha": "^3.2.0",