* Some refactors related repository model
* Move more methods out of repository
* Move repository into models/repo
* Fix test
* Fix test
* some improvements
* Remove unnecessary function
The current implementation of checkBranchName is highly inefficient
involving opening the repository, the listing all of the branch names
checking them individually before then using using opened repo to get
the tags.
This PR avoids this by simply walking the references from show-ref
instead of opening the repository (in the nogogit case).
Signed-off-by: Andrew Thornton <art27@cantab.net>