add subject_assignment! method
add test for subject_assignment!
update the rake file
Raise an error when manually trying to disqualify someone, but store_unqualified is false for the experiment.
Fix bug in Memory Storage.
Refactor rake tasks, and add tests for them.
Fix potential future issue
Add output to other rake tasks
Ruby 1.9 fix
Merge pull request #8 from Shopify/make_strong_version_of_store_assignment

Make subject_assignment! method