Bump json5 and ava

Removes [json5](https://github.com/json5/json5). It's no longer used after updating ancestor dependency [ava](https://github.com/avajs/ava). These dependencies need to be updated together.


Removes `json5`

Updates `ava` from 0.24.0 to 5.1.0
- [Release notes](https://github.com/avajs/ava/releases)
- [Commits](https://github.com/avajs/ava/compare/v0.24.0...v5.1.0)

---
updated-dependencies:
- dependency-name: json5
  dependency-type: indirect
- dependency-name: ava
  dependency-type: direct:development
...
Signed-off-by: Ndependabot[bot] <support@github.com>

package.json

@@ -56,7 +56,7 @@
     "languages"
   ],
   "devDependencies": {
-    "ava": "^0.24.0",
+    "ava": "^5.1.0",
     "husky": "1.0.0-rc.13",
     "nyc": "^11.3.0"
   }