auto-upgrade: add a test case with no permission to lock the repository
This show the current behavior when the repository is unlockable.
The current behavior is to abort, which is probably not great. Now that we have
a proper test, we can think about the behavior we want in a later changeset.
Differential Revision: https://phab.mercurial-scm.org/D12615
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).