Devstack provisioning breaks with new demo course

[timmc-edx]

The demo course was updated in openedx/openedx-demo-course#47 and devstack provisioning no longer works. This includes a new course key (new name and org) and the course content being moved a few directories deeper.

We have a temporary workaround to pin the old version of the demo course (#1274) but should put in a more permanent fix. The PR #1272 should fix this as far as the devstack repo itself is concerned, but there seem to be additional references to the course key outside of the devstack repo that might be causing problems.