tests: get nice error when test module is broken
Fixing coding style with the help of pep8 (wip)
tests: find out test modules automatically
Coding style: Silent pep8
A basic Branch type (subtype of Reference)
Implement Repository.branch_lookup. Constants for local and remote branches.
Implement Repository.listall_branches.
Implement Repository.create_branch.
Implement Branch.delete.
Implement Branch.is_head.
Implement Branch.move.
Implement Branch.branch_name.
Implement Branch.remote_name.
Implement Branch.upstream getter and setter.
Implement Branch.upstream_name getter.