First iteration of Travis CI integration.
Added Travis status icon (for testing).
Fix for Travis script.
Added caching to test script.
Added RDoc gem for older rubies.
Fixed Travis status icon in Readme.

It is however specific to GitHub user and branch, right now.
Removed assertion for system-generated error messages.
Helper for approximate assertions and nested list comparison.
Changed assertions for better error messages.
Minor helper fixes.
Added JRuby to Travis testing.
Added RubySL for Rubinius in Gemfile.
Reverted rbx group in Gemfile.

This is no longer necessary and was in fact causing problems for all environments.
http://www.benjaminfleischer.com/2013/12/05/testing-rubinius-on-travis-ci/
Moved non-essential Ruby versions to 'allowed-fail',
Fixed allow_failures in Travis CI config.
Changed newest Ruby to test to 2.1.

As suggested by @agarie
Merge pull request #26 from olavolav/travis-ci-testing

Travis CI integration