V3 payments 7 stripe (#7124)

* payments api: cancelSubscription

* some more tests for amazon payments

* promisifying amazon payments

* somehow payment stub is not working

* cleaning up tests

* renaming tests in api/v3/integration/payments

* improvements

* cleanup, lint

* fixes as per comments

* moment.zone() is back in.

* basic controller for stripe payments

* authWithUrl is in

* stripe cleanup

* making tests pass

* stripe bug fixes

* 400 error is right

* cleanup of sinon spy for fakeSend

* paypal payments

* lint of paypal

* require -> import

test/api/v3/integration/payments/POST-payments_paypal_ipn.test.js

@@ -0,0 +1,17 @@
+import {
+  generateUser,
+} from '../../../../helpers/api-integration/v3';
+
+describe('payments - paypal - #ipn', () => {
+  let endpoint = '/payments/paypal/ipn';
+  let user;
+
+  beforeEach(async () => {
+    user = await generateUser();
+  });
+
+  it('verifies credentials', async () => {
+    let result = await user.post(endpoint);
+    expect(result).to.eql({});
+  });
+});