Move get_image_meta_from_headers from images_client

Glance v1 images_client contains get_image_meta_from_headers() which
converts headers to returned body. However, most service clients'
methods don't convert like that.
Then this moves get_image_meta_from_headers() to common place like
the compute module from the service client.

Partially implements blueprint consistent-service-method-names

Change-Id: I40289be171239d45d81bdddcde55a1d68361a9f8
diff --git a/tempest/tests/common/test_image.py b/tempest/tests/common/test_image.py
new file mode 100644
index 0000000..fdd0ae8
--- /dev/null
+++ b/tempest/tests/common/test_image.py
@@ -0,0 +1,40 @@
+# Copyright 2016 NEC Corporation
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from tempest.common import image
+from tempest.lib.common import rest_client
+from tempest.tests import base
+
+
+class TestImage(base.TestCase):
+
+    def test_get_image_meta_from_headers(self):
+        resp = {
+            'x-image-meta-id': 'ea30c926-0629-4400-bb6e-f8a8da6a4e56',
+            'x-image-meta-owner': '8f421f9470e645b1b10f5d2db7804924',
+            'x-image-meta-status': 'queued',
+            'x-image-meta-name': 'New Http Image'
+        }
+        respbody = rest_client.ResponseBody(resp)
+        observed = image.get_image_meta_from_headers(respbody)
+
+        expected = {
+            'properties': {},
+            'id': 'ea30c926-0629-4400-bb6e-f8a8da6a4e56',
+            'owner': '8f421f9470e645b1b10f5d2db7804924',
+            'status': 'queued',
+            'name': 'New Http Image'
+        }
+        self.assertEqual(expected, observed)