Replace magic numbers with actual ids.
Use new rspec-rails conventions.

- Acceptance tests live in 'features' and include capybara.
- Request specs live in 'requests' or 'api' and don't use capybara.
Don't include capybara in request specs and use SessionHelper for feature specs only.
Spork has been defeated by Zeus.
Disable headless Jasmine runner for now.
Use new standard ruby-version file instead of .rvmrc.

It's safer, faster and doesn't require trusting.