build-sys: Avoid self-dependency in setup.py

The earlier 58a6e0e and later
455fc84 both break if the atomic
package is not actually installed on the system - as will be the case
with `mock/pbuilder` style builds.

It looks like OpenStack uses https://pypi.python.org/pypi/pbr which
presumably solves this problem.  I however am not super interested
right now in diving into that...I just want the thing to build.

Ansible just inserts the current dir in `sys.path`, which seems like a
simple hack, so let's do that.

setup.py

@@ -1,10 +1,13 @@
 #!/usr/bin/env python
 
 # Author: Dan Walsh <dwalsh@redhat.com>
+import sys
+import os
 from setuptools import setup
 import pkg_resources
 
-__version__ = pkg_resources.require('Atomic')[0].version
+sys.path.insert(0, os.path.abspath(os.getcwd()))
+from Atomic import __version__
 
 with open('requirements.txt') as f:
     requirements = f.read().splitlines()