chore(package): update ava to version 3.1.0

Closes #18

Author: greenkeeper[bot]

package.json

@@ -17,7 +17,7 @@
     "tagmeme": "0.0.7"
   },
   "devDependencies": {
-    "ava": "^0.25.0",
+    "ava": "^3.1.0",
     "babel-cli": "^6.24.1",
     "babel-core": "^6.25.0",
     "babel-preset-es2015": "^6.24.1",