Use TravisCI for continous integration

This pull request adds a TravisCI configuration file that will run both the maven build and the cucumber features against openjdk7, openjdk6, and oraclejdk7.  It also upgrades capybara to 2.0.2 which in turn upgrades selenium-web-driver and fixes the browser tests.  Finally, I also modified the `Rakefile` so that it fails when any of the shell commands fail.

In order for this to be complete we will also need @searls to sign in to TravisCI and activate the repository.  Here are the instructions for doing that, taken from the [getting started](http://about.travis-ci.org/docs/user/getting-started/) page.

*Step two: Activate GitHub Service Hook #*

*Once you're signed in go to your profile page. You'll see a list of your repositories. Flip the on/off switch for each repository that you want to hook up on Travis CI. Then visit the GitHub service hooks page for that project and paste your GitHub username and Travis token into the settings for the Travis service if it is not already pre-filled.*

*If your repository belongs to an organization or flipping the switch did not set up the hook, please set it up manually on GitHub. It will take just a couple of minutes.*