Move the singleton to a common location

Looks like it will be used by many other componts as well.

Change-Id: I2ac2b879db461d3fc9e70de84880a7e9b34076df
diff --git a/tempest/common/utils/misc.py b/tempest/common/utils/misc.py
new file mode 100644
index 0000000..8d945cf
--- /dev/null
+++ b/tempest/common/utils/misc.py
@@ -0,0 +1,27 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2012 OpenStack, LLC
+# 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.
+
+
+def singleton(cls):
+    """Simple wrapper for classes that should only have a single instance."""
+    instances = {}
+
+    def getinstance():
+        if cls not in instances:
+            instances[cls] = cls()
+        return instances[cls]
+    return getinstance
diff --git a/tempest/config.py b/tempest/config.py
index 89fa2d9..3b425ca 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -20,6 +20,7 @@
 import sys
 
 from tempest.common.utils import data_utils
+from tempest.common.utils.misc import singleton
 from tempest.openstack.common import cfg
 
 LOG = logging.getLogger(__name__)
@@ -370,18 +371,6 @@
         conf.register_opt(opt, group='boto')
 
 
-# TODO(jaypipes): Move this to a common utils (not data_utils...)
-def singleton(cls):
-    """Simple wrapper for classes that should only have a single instance."""
-    instances = {}
-
-    def getinstance():
-        if cls not in instances:
-            instances[cls] = cls()
-        return instances[cls]
-    return getinstance
-
-
 @singleton
 class TempestConfig:
     """Provides OpenStack configuration information."""