This project uses rspec-rails for testing and appraisal for managing multiple rails versions.
For running the specs for all the rails supported versions, you can run:
appraisal rspec
If you want to run the test suite for a singe rails version you can run:
appraisal <rails-version> rspec
So running appraisal rails-4-2 rspec
will run the test suite with rails 4.2 installed.
Additionally, if you want to run the specs using the version installed from the gemspec, you can just run:
rspec