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

@@ -40,7 +40,7 @@
     "egg-ci": "^1.6.0",
     "egg-mock": "^3.20.0",
     "egg-scripts": "^2.11.1",
-    "eslint": "^3.19.0",
+    "eslint": "^4.18.2",
     "eslint-config-egg": "^3.2.0",
     "webstorm-disable-index": "^1.1.2"
   },