Use mandrill for password resets and usernames in emails (#11277)

* use mandrill for password resets

* fix email id

* fix username in emails and tests

* fix tests

* fix package-lock

test/api/unit/libs/payments/payments.test.js

@@ -16,6 +16,7 @@ describe('payments/index', () => {
   beforeEach(async () => {
     user = new User();
     user.profile.name = 'sender';
+    user.auth.local.username = 'sender';
     await user.save();
 
     group = generateGroup({