chore(package): update eslint to version 6.8.0

Closes #30

Author: greenkeeper[bot]

package.json

@@ -47,7 +47,7 @@
     "babel-watch": "^2.0.3",
     "dmn": "^1.0.10",
     "doctoc": "^1.2.0",
-    "eslint": "^5.0.0",
+    "eslint": "^6.8.0",
     "eslint-plugin-ava": "^4.0.0",
     "eslint-plugin-filenames": "^1.1.0",
     "eslint-plugin-lean-imports": "^0.3.3",