Remove usage of ordereddict

This was only needed for Python < 2.7, but glanceclient's setup.cfg
already declares compatibility only with 2.7.

Change-Id: I80d42abf5dd5565da424a90a93545ba82ef7a58d

glanceclient/tests/unit/test_shell.py

@@ -15,10 +15,7 @@
 #    under the License.
 
 import argparse
-try:
-    from collections import OrderedDict
-except ImportError:
-    from ordereddict import OrderedDict
+from collections import OrderedDict
 import hashlib
 import logging
 import os