oeqa.utils.git: implement GitRepo.get_current_branch()

(From OE-Core rev: dcba2302adab47b398f1ce7d09c38828ea9ae426)

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/utils/git.py

@@ -46,4 +46,12 @@ class GitRepo(object):
             # Revision does not exist
             return None
 
+    def get_current_branch(self):
+        """Get current branch"""
+        try:
+            # Strip 11 chars, i.e. 'refs/heads' from the beginning
+            return self.run_cmd(['symbolic-ref', 'HEAD'])[11:]
+        except GitError:
+            return None
+