Remove deprecated NOVA_RAX_AUTH
Remove deprecated NOVA_RAX_AUTH

NOVA_RAX_AUTH has been deprecated in favor of a generic pluggable auth,
which in this case rackspace users can set OS_AUTH_SYSTEM=rackspace

Fixes bug 966329

Change-Id: Ie55fc36a0ac1cba61efa8bdd2f20809530d3365f

Shihta/python-novaclient,metacloud/python-novaclient,JioCloud/python-novaclient,takeshineshiro/python-novaclient,ntt-sic/python-novaclient,akash1808/python-novaclient,CCI-MOC/python-novaclient,guptaankita/python-novaclient,akash1808/python-novaclient,metacloud/python-novaclient,mat128/python-novaclient,Shihta/python-novaclient,JioCloud/python-novaclient,takeshineshiro/python-novaclient,mat128/python-novaclient,CCI-MOC/python-novaclient,ntt-sic/python-novaclient,guptaankita/python-novaclient