Mark intermittently failing test_send_remove_branch test as known failing.

dulwich/tests/compat/test_client.py

@@ -322,6 +322,9 @@ class DulwichClientTestBase(object):
             for r in result.refs.items():
                 dest.refs.set_if_equals(r[0], None, r[1])
 
+    # This test fails intermittently on my machine, probably due to some sort
+    # of race condition. Probably also related to #1015
+    @expectedFailure
     def test_send_remove_branch(self):
         with repo.Repo(os.path.join(self.gitroot, "dest")) as dest:
             dummy_commit = self.make_dummy_commit(dest)