Update dependency ava to v0.25.0

Author: renovate-bot

package.json

@@ -25,7 +25,7 @@
   "dependencies": {},
   "devDependencies": {
     "@aureooms/js-itertools": "3.4.0",
-    "ava": "0.19.1",
+    "ava": "0.25.0",
     "babel-cli": "6.26.0",
     "babel-polyfill": "6.26.0",
     "babel-preset-latest": "6.24.1",