Add debug level logs for TempAuth.authorize.

The function authorize in tempauth.py and keysthoneauth.py is very
important and frequently called in swift. But authorize in tempauth
seems hard to debug with nearly no logs here.

Change-Id: I3300a5a8d02743ff76e2ff86c51338ca24ddddcb
Fixes: bug #1129769
Merge "Add debug level logs for TempAuth.authorize."