Enable H407,H305,H307,E122 ignore E123

After bumping the hacking version to the 0.9.x series ignores were
added for several rules. This commit fixes the violations for a subset
of these rules and re-enables the checks.

E123 is ignored because this rule is ignored in the default pep8 by
default, due to a lack of consensus around it.

Change-Id: I8f14cd2ca6afc38d3fe8ee758272071111022896
diff --git a/tempest/tests/fake_identity.py b/tempest/tests/fake_identity.py
index 1900fc9..97098e1 100644
--- a/tempest/tests/fake_identity.py
+++ b/tempest/tests/fake_identity.py
@@ -13,9 +13,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import json
 
 import httplib2
-import json
 
 
 TOKEN = "fake_token"