Bump eslint from 3.19.0 to 6.6.0

Bumps [eslint](https://github.com/eslint/eslint) from 3.19.0 to 6.6.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](eslint/eslint@v3.19.0...v6.6.0)

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

package.json

@@ -32,7 +32,7 @@
     "coffee-script": "^1.12.6",
     "convert-source-map": "^1.5.0",
     "escodegen": "^1.8.1",
-    "eslint": "^3.19.0",
+    "eslint": "^6.6.0",
     "esprima": "^3.1.3",
     "estraverse": "^4.2.0",
     "nyc": "^8.4.0",