Re-add setuptools-git to setup.py

In 02f59a0768a56c084fa72ac9c1e47f1a819baadc we removed:

  setup_requires=['setuptools-git>=0.4'],

from setup.py file and it broke tarball generation in that some files
are now missing.

Change-Id: I53997b68a4a36cae63d191d63bc19ef459c228c4
Fixes: bug #1169295