Revert "added cancel method to payment gateway"
Revert "added cancel method to payment gateway"

This reverts commit 589c7220cf44a1e96a7a47df45b22cf4163be3b1.

ckk-scratch/spree_affirm,Affirm/spree_affirm,ckk-scratch/spree_affirm,sunilgowda/spree_affirm,sunilgowda/spree_affirm,sunilgowda/spree_affirm,Affirm/spree_affirm,Affirm/spree_affirm,ckk-scratch/spree_affirm