Bump eslint from 3.19.0 to 4.19.1

Bumps [eslint](https://github.com/eslint/eslint) from 3.19.0 to 4.19.1.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/compare/v3.19.0...v4.19.1)
Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -45,7 +45,7 @@
     "end-of-stream": "^1.1.0",
     "escape-html": "^1.0.3",
     "escape-string-regexp": "^1.0.5",
-    "eslint": "^3.18.0",
+    "eslint": "^4.19.1",
     "eslint-config-hypothesis": "^1.0.0",
     "eslint-plugin-mocha": "^4.8.0",
     "exorcist": "^0.4.0",