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

@@ -42,7 +42,7 @@
     "babel-preset-es2015": "^6.18.0",
     "commander": "^2.11.0",
     "coveralls": "^2.11.15",
-    "eslint": "^3.13.1",
+    "eslint": "^6.6.0",
     "eslint-plugin-flowtype": "^2.30.0",
     "eslint-plugin-import": "^2.2.0",
     "expect": "^1.20.2",