add quota.js, 100req/min limit

src/appmixer/zendesk/tickets/quota.js

@@ -0,0 +1,19 @@
+'use strict';
+
+module.exports = {
+
+    rules: [
+        {
+            // https://developer.zendesk.com/api-reference/introduction/rate-limits/
+            // Note that we are applying a conversvative rate limit regardless of the user's plan.
+            // The rate limit below is based on the 100req/min limit imposed by the Update ticket endpoint.
+            // It's better to stay conversvative than letting the requests error out leading to a bad user experience.
+            limit: 100,                       // the quota is 100 per 60 seconds
+            window: 1000 * 60,               // 60 seconds
+            throttling: 'window-sliding',
+            queueing: 'fifo',
+            resource: 'requests',
+            scope: 'userId'
+        }
+    ]
+};