Update travis config on @joshk's instructions
Test against 1.9.3 as well.
enable Travis CI irc notifications to #rails-contrib on irc.freenode.org
Added a .travis.yml config and travis specific ci script.
Don't install ruby-debug if running the test suite on Travis,
linecache19 is the main offender, very very slow.
And do not install pg if Travis is bundling the gems, pg will be setup
on Travis soon.