Drop MANIFEST.in - it's not needed by pbr
Drop MANIFEST.in - it's not needed by pbr

This patch removes `MANIFEST.in` file as pbr generates a
sensible manifest from git files and some standard files
and it removes the need for an explicit `MANIFEST.in` file.

Change-Id: I0914c0553ae3a28e9d2a883e91e926733d8e91df

huntxu/python-neutronclient,huntxu/python-neutronclient,openstack/python-neutronclient,noironetworks/python-neutronclient,noironetworks/python-neutronclient,openstack/python-neutronclient