chore(package): update ava to version 3.8.1

Closes #241

Author: greenkeeper[bot]

package.json

@@ -82,7 +82,7 @@
     "webpack-visualizer-plugin": "^0.1.11"
   },
   "devDependencies": {
-    "ava": "^0.25.0",
+    "ava": "^3.8.1",
     "babel-plugin-dynamic-import-node": "^1.2.0",
     "babel-plugin-module-resolver": "^3.1.1",
     "babel-plugin-transform-class-properties": "^6.24.1",