Do not remove python-pip package on Fedora-23
Do not remove python-pip package on Fedora-23

python on fedora 23 compiled with rewheel support,
in this case the python-pip is a required package, and cannot be
removed.

[1] http://pkgs.fedoraproject.org/cgit/python.git/tree/python.spec?id=3b6fac0339bab69ca5fbf2881568f0565ab0e252#n174

Change-Id: I499b7bec97c4360b32d156079f2b7f3923e3888a

richliu/devstack,group-policy/devstack,samgoon/devstack,thomasem/devstack,thomasem/devstack,avvocatodemarchis/devstack,dirkmueller/devstack,mssumanth/devstack,nawawi/openstack,bigswitch/devstack,bswartz/devstack,prithivm/branch01,bigswitch/devstack,richliu/devstack,dtroyer/devstack,dirkmueller/devstack,bswartz/devstack,dtroyer/devstack,openstack-dev/devstack,nawawi/openstack,avvocatodemarchis/devstack,mssumanth/devstack,noironetworks/devstack,Mahito/devstack,Mahito/devstack,varunarya10/devstack,group-policy/devstack,prithivm/branch01,samgoon/devstack,noironetworks/devstack,varunarya10/devstack,openstack-dev/devstack