chore(package): update ava to version 1.2.1

Closes #50

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
   },
   "devDependencies": {
     "@carsy/eslint-config": "^0.4.0",
-    "ava": "^0.25.0",
+    "ava": "^1.2.1",
     "coveralls": "^3.0.0",
     "eslint": "^4.19.1",
     "nyc": "^11.7.1",