python3: Work around httpretty issue
python3: Work around httpretty issue

Currently running tox.ini with py33 installation
fails because of a failure to read a unicode file
while installing httpretty.

Closes-Bug: #1241560

Change-Id: I6012c4fcca0d0354f0c1bdf4797f6e7409f7bf1c
Signed-off-by: Chuck Short <753a8074f04ffd62a8fff7516e3ae689be8e35ad@canonical.com>

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