feat(api): Add active user api

server/models/about.js

@@ -0,0 +1,25 @@
+import { createActiveUsers } from '../utils/about.js';
+
+
+module.exports = function(About) {
+  const activeUsers = createActiveUsers();
+  About.getActiveUsers = function getActiveUsers() {
+    // converting to promise automatically will subscribe to Observable
+    // initiating the sequence above
+    return activeUsers.toPromise();
+  };
+
+  About.remoteMethod(
+    'getActiveUsers',
+    {
+      http: {
+        path: '/get-active-users',
+        verb: 'get'
+      },
+      returns: {
+        type: 'number',
+        arg: 'activeUsers'
+      }
+    }
+  );
+};