Merge #15: Integrate Travis

commit deb59197d98e831670c71be1a13125f2725a7bcf
Author: Whyme Lyu <callme5long@gmail.com>
Date:   Wed Mar 27 09:57:57 2013 +0800

    A `rake travis` task

commit ddd76be0d1c88e7778291cff0aae01d35cf14fb7
Author: Whyme Lyu <callme5long@gmail.com>
Date:   Thu Mar 21 22:52:07 2013 +0800

    Gemfile and .travis.yml to get started