Add active_support to the app generator
Add active_support to the app generator

Because of this trace:
https://travis-ci.org/rspec/rspec-rails/jobs/120133080#L5065-L5080

rspec/rspec-rails,DarthSim/rspec-rails,DarthSim/rspec-rails,rspec/rspec-rails,rspec/rspec-rails,DarthSim/rspec-rails