Fix the removal of config.skip_(unless|if)_config decorators

These decorators were removed in I54a001cb562a8aac91537bf61e82a7e7d3498788
without a proper deprecation period. My bad.

Change-Id: Icc007047a8e9a527d48374b3efcec8cc5fd1be08

releasenotes/notes/deprecate-skip_unless_config-decorator-64c32d588043ab12.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - The ``skip_unless_config`` and ``skip_if_config`` decorators in the
+    ``config`` module have been deprecated and will be removed in the Queens
+    dev cycle. Use the ``testtools.skipUnless`` (or a variation of) instead.

tempest/config.py

@@ -19,6 +19,7 @@ import functools
 import os
 import tempfile
 
+import debtcollector.removals
 from oslo_concurrency import lockutils
 from oslo_config import cfg
 from oslo_log import log as logging
@@ -1191,6 +1192,8 @@ class TempestConfigProxy(object):
 CONF = TempestConfigProxy()
 
 
+@debtcollector.removals.remove(
+    message='use testtools.skipUnless instead', removal_version='Queens')
 def skip_unless_config(*args):
     """Decorator to raise a skip if a config opt doesn't exist or is False
 
@@ -1229,6 +1232,8 @@ def skip_unless_config(*args):
     return decorator
 
 
+@debtcollector.removals.remove(
+    message='use testtools.skipIf instead', removal_version='Queens')
 def skip_if_config(*args):
     """Raise a skipException if a config exists and is True