Add integration tests for the Label command
Refactor CheckMilestone to inherit from GitRepoCommand
Add test for local tag existence before querying the log

- Fails with Stop command if tag unfound
- Add unit test to check tag non-existence logic
Add passing check-milestone test and test for non existing milestone
In rebase, fail with gracious message if specified PR does not exist
Explicitely specify expected Exception type if pull request not found
Add integration test for unfound PR in `scc rebase`
Fix parse_body() method when PR has no body
Add basic test for `scc version` command
Add basic integration test for `scc unrebased-prs` command
In UnrebasedPRs, reuse the top-level parse_pr() method
merge master -D org -I include -E exclude: PR 94 (Update-submodules PR update)
merge master -D org -I include -E exclude: PR 96 (Rebase nopr)
merge master -D org -I include -E exclude: PR 97 (Integration tests migration (final))