0.3.0

 * Added method to set each credential and option individually in place of setCredentials and setApiCredentials methods.
* Cleaned up whitespace and indenting.
* Changed a few method names to use camel case for consistency.
* Replaced "environment" option with "verifySSL" option for clarity.
* Refactored Admin API and Payment API request methods to one method.
* Change default response format to Array instead of JSON.