Make Jenkins use custom test runner (DiscoveryRunner)

Without this Jenkins finds no tests to run.
Change the urls.py to use the new django-registration views
Change to use assing_perm instead of assign.

This makes it compatible with the latest version of django-guardian
Merge branch 'upgrade_software' of https://github.com/daniell/econsensus into daniell-upgrade_software
Be explicit about version of django-registration (and a number of other packages)