Fix and enable gating on H306

H306 - module imports should be in alphabetical order

Change-Id: I1f8fc25b0e6ca23c21c90bda420f42a45141c2e2

glanceclient/v1/client.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 from glanceclient.common import http
-from glanceclient.v1 import images
 from glanceclient.v1 import image_members
+from glanceclient.v1 import images
 
 
 class Client(http.HTTPClient):

glanceclient/v1/shell.py

@@ -19,9 +19,9 @@ import argparse
 import copy
 import sys
 
-from glanceclient import exc
-from glanceclient.common import utils
 from glanceclient.common import progressbar
+from glanceclient.common import utils
+from glanceclient import exc
 from glanceclient.openstack.common import strutils
 import glanceclient.v1.images