Fix GitLab merge request fetch

Reverts one chunk of e58373e

Author: jayvdb

git_repo/services/ext/gitlab.py

@@ -312,7 +312,7 @@ def request_fetch(self, user, repo, request, pull=False, force=False):
                     local_branch_name = 'requests/gitlab/{}'.format(request)
                     self.fetch(
                         remote,
-                       'merge_requests/{}/head'.format(request),
+                       'merge-requests/{}/head'.format(request),
                         local_branch_name,
                         force
                     )

tests/integration/test_gitlab.py

@@ -241,7 +241,7 @@ def test_19_request_fetch(self):
         self.action_request_fetch(namespace='guyzmo',
                 repository='git-repo',
                 request='4',
-                remote_branch='merge_requests',
+                remote_branch='merge-requests',
                 local_branch='requests/gitlab')
 
     def test_19_request_fetch__bad_request(self):