Remove ordereddict from requirements

Ordereddict was required for py26 support. Since we have
dropped support for py26 (we are no longer gating on it) we
should remove it as a requirement and remove references
to it in the code.

Change-Id: I648edbb5d0b51c003f08f5f5c4ce700128032b38
Partial-bug: 1445827

glance/common/property_utils.py

@@ -12,12 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from collections import OrderedDict
 import ConfigParser
 import re
-try:
-    from collections import OrderedDict
-except ImportError:
-    from ordereddict import OrderedDict
 
 from oslo_config import cfg
 from oslo_log import log as logging

glance/common/swift_store_utils.py

@@ -12,11 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from collections import OrderedDict
 import ConfigParser
-try:
-    from collections import OrderedDict
-except ImportError:
-    from ordereddict import OrderedDict
 
 from oslo_config import cfg
 from oslo_log import log as logging

requirements.txt

@@ -21,7 +21,6 @@ httplib2>=0.7.5
 kombu>=2.5.0
 pycrypto>=2.6
 iso8601>=0.1.9
-ordereddict
 oslo.config>=1.9.3,<1.10.0  # Apache-2.0
 oslo.concurrency>=1.8.0,<1.9.0         # Apache-2.0
 oslo.context>=0.2.0,<0.3.0                     # Apache-2.0