Update django-cronjobs.

This is a version that actually supports being installed through pip.
[bug 1035319] Possible fix for travis.
[bug 1035319] More fixes.
[bug 1035319] Attempt to fix travis again.
[bug 1035319] Travis tell me what's wrong.
[bug 1035319] Updated reqs with another sha hash.
[bug 1035319] First draft fix for cronjobs.
[bug 1035319] Added back rscripts
[bug 1035319] Re-added pythonpath to crongen.
[bug 1035319] Possible fix for gen-crons.
[bug 1035319] Fix for the last time hopefully.
Change default python in gen-cron.py.
[bug 1035319] Another maybe fix.
Updated product_details sha.
[bug 1035319] Fixed statsd version.
[bug 1035319] Temporary fix for jingo-minify.

This needs to be updated after the PR is merged into master at:
https://github.com/jsocol/jingo-minify/pull/41
[bug 1035319] Fixed virtualenv deployment script.