Update dependency ava to v3

Author: renovate-bot

package.json

@@ -26,7 +26,7 @@
     "xml2js": "^0.4.19"
   },
   "devDependencies": {
-    "ava": "2.4.0",
+    "ava": "3.8.1",
     "eslint-config-prettier": "6.4.0",
     "xo": "0.25.3"
   },