• Adds support for card purchases
• Adds custom validation for orderNumber, cryptType, and description parameters
• Adds tests for purchase requests with missing or invalid paymentMethod, orderNumber, cryptType, cardReference, card, description, and amount.

Allow crypt_type to be configured

• add omnipay test cases
• add camel case for omnipay method accessors
• add travis ci support
• add style ci support
• add coveralls support
• add phpcs.xml for PHP CodeSniffer