Replace six.iteritems() with .items()

1.As mentioned in [1], we should avoid using six.iteritems to achieve
iterators. We can use dict.items instead, as it will return iterators
in PY3 as well. And dict.items/keys will more readable.
2.In py2, the performance about list should be negligible, see the
link [2].
[1] https://wiki.openstack.org/wiki/Python3
[2] http://lists.openstack.org/pipermail/openstack-dev/2015-June/066391.html

Change-Id: I45fa65427318e1c35bb521de46e81ea12ca7b770

murano_tempest_tests/services/artifacts/artifacts_client.py

@@ -20,7 +20,6 @@ from tempest import config
 from tempest.lib.common import rest_client
 
 from murano_tempest_tests import utils
-import six
 
 CONF = config.CONF
 
@@ -132,7 +131,7 @@ class ArtifactsClient(rest_client.RestClient):
             'tags': manifest.get('Tags', []),
             'class_definitions': package.classes.keys()
         }
-        for k, v in six.iteritems(body):
+        for k, v in body.items():
             package_draft[k] = v
 
         inherits = utils.get_local_inheritance(package.classes)

murano_tempest_tests/tests/api/application_catalog/artifacts/test_versioning.py

@@ -13,7 +13,6 @@
 #    under the License.
 
 import os
-import six
 import testtools
 
 from tempest import config
@@ -60,7 +59,7 @@ class TestVersioning(base.BaseArtifactsTest):
 
     @classmethod
     def resource_cleanup(cls):
-        for pkg in six.itervalues(cls.packages):
+        for pkg in cls.packages.values():
             cls.artifacts_client.delete_package(pkg['id'])
         map(os.remove, cls.abs_archive_paths)
         super(TestVersioning, cls).resource_cleanup()

murano_tempest_tests/tests/api/application_catalog/artifacts/test_versioning_negative.py

@@ -13,7 +13,6 @@
 #    under the License.
 
 import os
-import six
 import testtools
 
 from tempest import config
@@ -54,7 +53,7 @@ class TestVersioningNegative(base.BaseArtifactsTest):
 
     @classmethod
     def resource_cleanup(cls):
-        for pkg in six.itervalues(cls.packages):
+        for pkg in cls.packages.values():
             cls.artifacts_client.delete_package(pkg['id'])
         map(os.remove, cls.abs_archive_paths)
         super(TestVersioningNegative, cls).resource_cleanup()

murano_tempest_tests/utils.py

@@ -319,8 +319,8 @@ class Package(FileWrapperMixin):
     def classes(self):
         if not hasattr(self, '_classes'):
             self._classes = {}
-            for class_name, class_file in six.iteritems(
-                    self.manifest.get('Classes', {})):
+            for class_name, class_file in (
+                    self.manifest.get('Classes', {}).items()):
                 filename = "Classes/%s" % class_file
                 if filename not in self.contents.namelist():
                     continue
@@ -431,7 +431,7 @@ class Package(FileWrapperMixin):
     def _get_direct_deps(package, base_url, path):
         result = []
         if 'Require' in package.manifest:
-            for dep_name, ver in six.iteritems(package.manifest['Require']):
+            for dep_name, ver in package.manifest['Require'].items():
                 try:
                     req_file = Package.from_location(
                         dep_name,
@@ -480,7 +480,7 @@ class NamespaceResolver(object):
 
 def get_local_inheritance(classes):
     result = {}
-    for class_name, klass in six.iteritems(classes):
+    for class_name, klass in classes.items():
         if 'Extends' not in klass:
             continue
         ns = klass.get('Namespaces')