This filters out historical enrollment data for courses that started before enrollment events went live (Dec 3, 2013)
Loosen access restrictions on temp working dir to match logging dir.

This will clear up autogather-related permissions errors in Hive.
Hardcode pipeline to use Python 2.7 (in anticipation of Opaque Keys integration).
Update virtualenv_python argument.
Fix blacklist acceptance test
Compute historical activity
Merge pull request #12 from edx/gabe/fix-blacklist

Fix blacklist acceptance test
Merge pull request #11 from edx/gabe/user-activity-per-week

Compute historical user activity
Revert to using Python 2.6 for the time being
Merge pull request #13 from edx/gabe/use-py26

Revert to using Python 2.6 for the time being
Use less disk space for acceptance tests
Merge pull request #14 from edx/gabe/use-less-disk-space

Use less disk space for acceptance tests