Fix python 2 and 3 compatibility issue with six

httplib and ConfigParser are available in python2 but
not in python3.
ref:http://www.diveintopython3.net/porting-code-to-python-3-with-2to3.html

Targets blueprint: murano-python-3-support
Change-Id: I5164c9208f1626ea60cde47ded6cd74fbff919fd

murano/api/versions.py

@@ -12,10 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import httplib
-
 from oslo_config import cfg
 from oslo_serialization import jsonutils
+from six.moves import http_client
 import webob.dec
 
 from murano.common import wsgi
@@ -48,7 +47,7 @@ class Controller(object):
         ])
 
         response = webob.Response(request=req,
-                                  status=httplib.MULTIPLE_CHOICES,
+                                  status=http_client.MULTIPLE_CHOICES,
                                   content_type='application/json')
         response.body = jsonutils.dumps(dict(versions=version_objs))
         return response

tools/install_venv.py

@@ -18,10 +18,11 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import ConfigParser
 import os
 import sys
 
+from six.moves import configparser
+
 import install_venv_common as install_venv  # flake8: noqa
 
 
@@ -57,7 +58,7 @@ def main(argv):
     pip_requires = os.path.join(root, 'requirements.txt')
     test_requires = os.path.join(root, 'test-requirements.txt')
     py_version = "python%s.%s" % (sys.version_info[0], sys.version_info[1])
-    setup_cfg = ConfigParser.ConfigParser()
+    setup_cfg = configparser.configparser()
     setup_cfg.read('setup.cfg')
     project = setup_cfg.get('metadata', 'name')