Add support to TrustCommercePaymentProcess for utilizing caller provided account credentials.
Use property defined trust commerce credentials in non production environment.
Add business logic to determine trust commerce account credentials, then provide to trust commerce payment process
Allow UsernamePasswordCredentials to enforce conditions (only requires username be not null)
Provide credentials to trustCommercePaymentProcess methods
Add payment gateway types to conference costs table.
Add trust commerce credit card payment functional test.