chore: update dependency eslint to v6.8.0

Author: renovate-bot

package-lock.json

@@ -97,7 +97,7 @@
     "@babel/register": "7.7.7",
     "ava": "2.4.0",
     "babel-eslint": "10.0.3",
-    "eslint": "6.7.2",
+    "eslint": "6.8.0",
     "eslint-config-prettier": "6.7.0",
     "eslint-plugin-prettier": "3.1.2",
     "flow-bin": "0.114.0",