Configure Travis CI
Squashed commit of the following:

commit 3fcbf2fc855c36a45fe4e4b2a7efdb377ed783b4
Author: Vicente Alencar <vicente@jusbrasil.com.br>
Date:   Tue Sep 24 15:55:10 2013 -0300

    Improves the implementation of is_element_present and removes extra
    blank line.

commit ceeb7283fc86805d6e6aab34092c13b0ee41f426
Author: Vicente Alencar <vicente@jusbrasil.com.br>
Date:   Tue Sep 24 15:27:18 2013 -0300

    Adds is_element_present default implementation.