build(deps-dev): bump eslint from 3.14.1 to 4.18.2

Bumps [eslint](https://github.com/eslint/eslint) from 3.14.1 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@v3.14.1...v4.18.2)

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

Author: dependabot[bot]

package.json

@@ -5,7 +5,7 @@
     "build": "yarn && gulp && node scripts/build"
   },
   "devDependencies": {
-    "eslint": "^3.9.1",
+    "eslint": "^4.18.2",
     "gulp": "^3.9.1",
     "gulp-sass": "^3.0.0",
     "http-server": "*",