setup: Don't directly import the version file

Load the version module explicitly by defining its path. Weird
situations may occur if you have a version of the project already
installed in your system and you import project modules in setup.py

setup.py

 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2011-2015 GRNET S.A.
+# Copyright (C) 2011-2016 GRNET S.A.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,16 +16,17 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import image_creator
 from os.path import dirname, abspath, join
-
 from setuptools import setup, find_packages
+from imp import load_source
 
-README = join(dirname(abspath(__file__)), 'README.md')
+CWD = dirname(abspath(__file__))
+README = join(CWD, 'README.md')
+VERSION = join(CWD, 'image_creator', 'version.py')
 
 setup(
     name='snf_image_creator',
-    version=image_creator.__version__,
+    version=getattr(load_source('version', VERSION), "__version__"),
     description='Command line tool for creating images',
     long_description=open(README).read(),
     url='https://github.com/grnet/snf-image',