HTTPretty: update to 0.7.1
HTTPretty: update to 0.7.1

The 0.7.1 release has a fix for the parse_querystring function, which raised a
TypeError on Python 3.3. See:

https://github.com/gabrielfalcao/HTTPretty/commit/5c6e77615f4083b9daf4a0148349f3185dcaff05

This helps fix some tests on Python3.3.

Change-Id: I8f28c5dfdcb25b2c131a4b8866547025064caac6

darren-wang/ksc,metacloud/python-keystoneclient,alexpilotti/python-keystoneclient,magic0704/python-keystoneclient,jamielennox/python-keystoneclient,darren-wang/ksc,magic0704/python-keystoneclient,jamielennox/python-keystoneclient,sdpp/python-keystoneclient,Mercador/python-keystoneclient,metacloud/python-keystoneclient,klmitch/python-keystoneclient,sdpp/python-keystoneclient,klmitch/python-keystoneclient,ging/python-keystoneclient,alexpilotti/python-keystoneclient,Mercador/python-keystoneclient,ging/python-keystoneclient,jamielennox/python-keystoneclient