Update eslint to version 6.8.0 (#305)

Closes #282

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

Author: RyanZim

package.json

@@ -34,7 +34,7 @@
   "devDependencies": {
     "ava": "^2.4.0",
     "coveralls": "^3.0.0",
-    "eslint": "^5.0.0",
+    "eslint": "^6.8.0",
     "eslint-config-problems": "2.0.0",
     "nyc": "^15.0.0",
     "postcss-import": "^12.0.0",