appraisal gem lets us test against multiple ruby/rails versions
appraisal -- should not commit lock files; also, rename gemfiles
appraisal -- capybara lower version for previous rails
appraisal -- travis.yml allow failures for earlier; remove rake clean craps
appraisal -- capybara downgrade for ruby 1.9.2 (le sigh)
appraisals -- devise per rails version
travis.yml -- run db migrate beforehand
appraisal -- can run tests again
minimum ruby version 1.9.2
backwards compatibility -- rails 3 requires manual renaming index
backwards compatility -- older devise (for rails 3.0) not use secret_key
backwards compatibility -- moving install_tasks before load engine.rake
backwards compatibility -- removing index before renaming table
backwards compatibility -- remove "remove_index"
backwards compatibility -- validates uniqueness: not unique:
appraisal -- rails-3.0 failing (not sure why) -- exclude for now for travis' sake
backwards compatibility -- rails 3.2 issue with vault uniqueness in code
backwards compatibility -- use find_or_create_by not first_or_create
backwards compatibility -- Vault.for_owner find_or_create to where().first||create
backwards compatibility -- devise secret_key vs. secret_token y4y