Proper deprecation for Manager.api

base.Manager's api property wasn't properly deprecated since all it
had was documentation. Proper deprecation requires use of warnings
and documentation.

bp deprecations

Change-Id: Ic5e218151e9b3f3b66f78729052680691d5ad582

keystoneclient/base.py

@@ -21,6 +21,7 @@ Base utilities to build API operation managers and objects on top of.
 
 import abc
 import functools
+import warnings
 
 import six
 from six.moves import urllib
@@ -91,8 +92,17 @@ class Manager(object):
 
     @property
     def api(self):
-        """Deprecated. Use `client` instead.
+        """The client.
+
+        .. warning::
+
+            This property is deprecated as of the 1.7.0 release in favor of
+            :meth:`client` and may be removed in the 2.0.0 release.
+
         """
+        warnings.warn(
+            'api is deprecated as of the 1.7.0 release in favor of client and '
+            'may be removed in the 2.0.0 release', DeprecationWarning)
         return self.client
 
     def _list(self, url, response_key, obj_class=None, body=None, **kwargs):

keystoneclient/tests/unit/test_base.py

@@ -94,7 +94,8 @@ class ManagerTest(utils.TestCase):
         self.mgr.resource_class = base.Resource
 
     def test_api(self):
-        self.assertEqual(self.mgr.api, self.client)
+        with self.deprecations.expect_deprecations_here():
+            self.assertEqual(self.mgr.api, self.client)
 
     def test_get(self):
         get_mock = self.useFixture(mockpatch.PatchObject(