Bump cacheable-request and ava

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


Removes `cacheable-request`

Updates `ava` from 3.15.0 to 5.2.0
- [Release notes](https://github.com/avajs/ava/releases)
- [Commits](avajs/ava@v3.15.0...v5.2.0)

---
updated-dependencies:
- dependency-name: cacheable-request
  dependency-type: indirect
- dependency-name: ava
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -24,7 +24,7 @@
     "@types/jquery": "^3.5.5",
     "@types/ractive": "^0.7.27",
     "autoprefixer": "^9.6.1",
-    "ava": "^3.15.0",
+    "ava": "^5.2.0",
     "babel-cli": "^6.26.0",
     "babel-core": "^6.26.3",
     "babel-loader": "^8.0.6",