Allows identity endpoint to be specified as URI

Deprecates the piecemeal identity URL buildup and
replaces with a simple uri configuration setting.
Gets rid of the /tokens path stuff that was not
necessary to have in configuration file.

Change-Id: I5e80177073f756781f813438d054fede2d6334a3
diff --git a/tempest/clients.py b/tempest/clients.py
index 0bb1752..98ae3f6 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -164,7 +164,7 @@
                    "tenant_name: %(tenant_name)s") % locals()
             raise exceptions.InvalidConfiguration(msg)
 
-        self.auth_url = self.config.identity.auth_url
+        self.auth_url = self.config.identity.uri
 
         if self.config.identity.strategy == 'keystone':
             client_args = (self.config, self.username, self.password,