Add .travis.yml
Add .travis.yml

After @flarnie fixed support for Ruby 1.8.7, I want to make sure that
this keeps working. I'm therefore adding a Travis integration, where I
plan to run rspec tests for 1.8.7, 1.9.3 and 2.1.2.

lencioni/import-js,Galooshi/import-js,lencioni/import-js,trotzig/import-js,trotzig/import-js,flarnie/import-js,trotzig/import-js,flarnie/import-js,lencioni/import-js