Make server action methods[a-c] use **kwargs

As we discussed on
http://lists.openstack.org/pipermail/openstack-dev/2015-July/068864.html
All http POST/PUT methods need to contain **kwargs as their arguments.
This patch makes server action methods[a-c] use **kwargs.

Partially implements blueprint consistent-service-method-names

Change-Id: I62deef121ef74152474976d5619ed1bbb0e051b2
diff --git a/tempest/api/compute/servers/test_server_rescue.py b/tempest/api/compute/servers/test_server_rescue.py
index 96ce45e..1552848 100644
--- a/tempest/api/compute/servers/test_server_rescue.py
+++ b/tempest/api/compute/servers/test_server_rescue.py
@@ -116,7 +116,8 @@
         self.addCleanup(self._unrescue, self.server_id)
 
         # Add Security group
-        self.servers_client.add_security_group(self.server_id, self.sg_name)
+        self.servers_client.add_security_group(self.server_id,
+                                               name=self.sg_name)
 
         # Delete Security group
         self.servers_client.remove_security_group(self.server_id,