update readme
update readme

SarahNoel/node-stripe-charge,mjhea0/node-stripe-charge,quintendf/node_stripe,yalcindo/stripeFromMike,lingqingmeng/preorder,yalcindo/stripeFromMike,amberwoodrow/node-stripe-charge,amberwoodrow/node-stripe-charge,lingqingmeng/preorder,mjhea0/node-stripe-charge,kolbeypruitt/mtm_official,quintendf/node_stripe,jpca999/node-stripe-charge,jpca999/node-stripe-charge,SarahNoel/node-stripe-charge,kolbeypruitt/mtm_official