Fix for setuptools issue (version creep)

Version locking to fix. (Thanks James Wettenhall for the fix).

Traceback (most recent call last):
  File "bin/django", line 67, in <module>
    sys.exit(djangorecipe.manage.main('tardis.settings'))
...
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2328, in insert_on
    "with distribute. Found one at %s" % str(self.location))
ValueError: A 0.7-series setuptools cannot be installed with distribute. Found one at /opt/mytardis/releases/a549cd05272afe8f16c2fe5efe8158490acbde82/eggs/setuptools-0.7.2-py2.7.egg