update dispatcher to allow for dynamic imports until webpack plugin is updated

app/assets/javascripts/dispatcher.js

@@ -111,6 +111,8 @@ import Activities from './activities';
         return false;
       }
+      const fail = () => Flash('Error loading dynamic module');
+
       path = page.split(':');
       shortcut_handler = null;
@@ -545,7 +547,7 @@ import Activities from './activities';
           new CILintEditor();
           break;
         case 'users:show':
-          new UserCallout();
+          import('./pages/users/show').then(m => m.default()).catch(fail);
           break;
         case 'admin:conversational_development_index:show':
           new UserCallout();

app/assets/javascripts/pages/users/show/index.js

+import UserCallout from '~/user_callout';
+
+export default () => new UserCallout();