Add service_catalog property

Add a property for getting the service catalog. Although most of the
time a user should not need to grab this directly, it can be invaluable
in debugging situations - and is a public method because there is an
ansible module that wants to directly expose it.

Change-Id: If54cb94fc9a80f1dabe90b46ed2f62d8fcb8460f

shade/__init__.py

@@ -228,6 +228,11 @@ class OpenStackCloud(object):
                     "Error authenticating to the keystone: %s " % e.message)
         return self._keystone_session
 
+    @property
+    def service_catalog(self):
+        return self.keystone_session.auth.get_access(
+            self.keystone_session).service_catalog.get_data()
+
     @property
     def auth_token(self):
         if not self._auth_token: