Bump ava from 3.8.2 to 3.15.0

Bumps [ava](https://github.com/avajs/ava) from 3.8.2 to 3.15.0.
- [Release notes](https://github.com/avajs/ava/releases)
- [Commits](avajs/ava@v3.8.2...v3.15.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -30,7 +30,7 @@
   },
   "devDependencies": {
     "@types/axios": "^0.14.0",
-    "ava": "^3.8.2",
+    "ava": "^3.15.0",
     "axios": "^0.21.1",
     "form-data": "^3.0.0",
     "prettier": "1.18.2"