added 2.1.0 to .travis.yml
fixed
added rbx to allow_failures matrix
refactor
Fix SiteAPI search_card required params
Bump to version 0.2.4
PayPal Support

* Add entry_tran_paypal and exec_tran_paypal.
* Note: This is not complete yet. We are still having problems with
        executing in the test environment.
Merge branch 'master' of github.com:diskshima/gmo-payment-ruby