Update to rails 3.2.13 and lock rails version in Gemfile.
Use newer VCR syntax to get rid of warning.
Add Repository#lesson.
Update mocha and set require to false in Gemfile.
Refactor existing models and update fixtures.
Add database_cleaner.
Update schema.rb.
Refactor existing models and update fixtures.
Use truncation strategy for clearing the database.
Add lesson importer.