Update eslint-ava-rule-tester to the latest version 🚀 (#42)

* chore(package): update eslint-ava-rule-tester to version 4.0.0

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -19,7 +19,7 @@
     "codecov": "^3.6.1",
     "eclint": "^2.8.1",
     "eslint": "^6.5.1",
-    "eslint-ava-rule-tester": "^3.0.0",
+    "eslint-ava-rule-tester": "^4.0.0",
     "eslint-plugin-eslint-plugin": "^2.1.0",
     "nyc": "^14.1.1"
   },