Remove BraintreeCard import from BTVenmoDriver
Remove BraintreeCard import from BTVenmoDriver

Venmo no longer depends on BraintreeCard, so this unused import
statement caused pod lib lint to fail.

billCTG/braintree_ios,Feverup/braintree_ios,billCTG/braintree_ios,apascual/braintree_ios,apascual/braintree_ios,Feverup/braintree_ios,billCTG/braintree_ios,apascual/braintree_ios,braintree/braintree_ios,braintree/braintree_ios,braintree/braintree_ios,apascual/braintree_ios,braintree/braintree_ios,billCTG/braintree_ios,Feverup/braintree_ios,Feverup/braintree_ios,billCTG/braintree_ios