chore(package): update ava to version 3.7.0

Closes #103

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "url": "https://github.com/andrejewski/himalaya/issues"
   },
   "devDependencies": {
-    "ava": "^0.25.0",
+    "ava": "^3.7.0",
     "babel-core": "^6.24.0",
     "babel-plugin-istanbul": "^4.0.0",
     "babel-polyfill": "^6.23.0",