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] <[email protected]>

Author: dependabot[bot]

package.json

@@ -78,7 +78,7 @@
     "bunyan": "^1.8.12",
     "chai": "^3.5.0",
     "chai-as-promised": "^7.1.1",
-    "eslint": "^3.16.1",
+    "eslint": "^6.6.0",
     "eslint-config-airbnb-base": "^11.1.0",
     "eslint-plugin-import": "^2.2.0",
     "istanbul": "^1.1.0-alpha.1",