adding the capture method (environment) to data cash

Customer getting a 401 error with Data Cash.  Seems to be caused by them using that account for multiple things, and us not explicitly stating that we are an eCommerce environment.

Here's their documentation: https://datacash.custhelp.com/app/answers/detail/a_id/318/~/return-code-190---no-capture-method-specified

@melari 
@odorcicd