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

dragonflow already uses PBR:- setuptools.setup(
	setup_requires=['pbr>=1.8'],
	pbr=True)

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: I060a1d6de972b01c19381f3fe1b5b88887eb04a7
Closes-Bug: #1608980

openstack/dragonflow,openstack/dragonflow,openstack/dragonflow