PR_template: ensure tests are added checkbox
Add a checkbox which states that all added or
changed functionality is tested.
@@ -25,3 +25,4 @@ the terms of the Apache 2.0 license.
- [ ] Any newly added `unsafe` code is properly documented.
- [ ] Any API changes are reflected in `firecracker/swagger.yaml`.
- [ ] Any user-facing changes are mentioned in `CHANGELOG.md`.
+- [ ] All added/changed functionality is tested.
