Remove use of tenant in common/context.py

Tenant has been removed from context.
Fixes UTs and pep8.

Signed-off-by: Spyros Trigazis <[email protected]>
Change-Id: I10daa22b614aab456b837c03278eb04da0355ff7

Author: strigazi

magnum/common/context.py

@@ -42,7 +42,7 @@ def __init__(self, auth_token=None, auth_url=None, domain_id=None,
         """
         super(RequestContext, self).__init__(auth_token=auth_token,
                                              user_id=user_name,
-                                             tenant=project_name,
+                                             project_id=project_name,
                                              is_admin=is_admin,
                                              read_only=read_only,
                                              show_deleted=show_deleted,