andrew/split — pull request #83 by philnash (2012-11-07 16:35:53+00:00)
Title: Getting negative non-finished rates when using finished(:reset => false)

During testing we've found that if users go through a test that is set to not reset (finished(experiment_name, :reset => false)) and then go through again that the completion rate is incremented even though the participation rate isn't.

It turned out that the clean_old_versions method was removing the key experiment_name:version:finished key from the session.

This fix makes clean_old_versions ignore the current finished experiment as well as the current experiment.