chore(package): update ava to version 3.5.2

Closes #158

Author: greenkeeper[bot]

package.json

@@ -43,7 +43,7 @@
     "tom-sawyer": "^0.1.5"
   },
   "devDependencies": {
-    "ava": "^0.25.0",
+    "ava": "^3.5.2",
     "eslint": "5.0.1",
     "minimist": "1.2.0",
     "nyc": "^12.0.1",