Fix bugs in Git utility functions:  - nimp.utils.git.get_branch() would fail if more than one branch were present  - nimp.utils.git.get_version() would fail to detect duplicate dates when    occurring at the same minute.
Fix bugs in Git utility functions:
 - nimp.utils.git.get_branch() would fail if more than one branch were present
 - nimp.utils.git.get_version() would fail to detect duplicate dates when
   occurring at the same minute.

dontnod/nimp