pay: properly execute the resolveSuccess callback on payment success

With this commit, we ensure that the trigger to update the UI upon
payment success is actually triggered. Previously, we would simply
reference the function rather than calling it directly.

Author: Roasbeef

packages/lightning-core/pay/reducer.js

@@ -48,12 +48,11 @@ export const actions = {
         .then(() => {
           const payments = dispatch(actions.sendPayment())
           payments.on('data', function(payment) {
-              }
-              else {
-                  resolveSuccess
               if (payment.payment_error != "") {
                   // TODO(roasbeef): need to switch and properlu display errors
                   rejectError({message: "Payment route failure"})
+              } else {
+                  resolveSuccess()
               }
           })
           payments.on('error', rejectError)
@@ -85,7 +84,7 @@ export const actions = {
   }),
   subscribePayments: () => ({
     [GRPC]: {
-      method: 'sendPayment',
+      method: 'subscribePayments',
       types: SUBSCRIBE_PAYMENT,
       stream: true,
     },