Micro PR for Flyers categorySlug migration (#108)

* Add migration script to update data based on new Flyers schema

* Update Flyer trendiness

* Fix comments

* Clean up syntax for get trending flyers

* Remove unnecessary createSpecificsByIndex function

* Fix TypeScript compilation error

* Update migration script to account for category slug

* Fix formatting for flyers test

migrations/update-flyers-model.js

@@ -9,6 +9,7 @@ module.exports = {
         $set: {
           organization: { $first: '$organizations' },
           organizationSlug: { $first: '$organizationSlugs' },
+          categorySlug: { $first: '$organizations.categorySlug' },
         },
       },
       {
@@ -31,7 +32,7 @@ module.exports = {
         },
       },
       {
-        $unset: ['organization', 'organizationSlug'],
+        $unset: ['organization', 'organizationSlug', 'categorySlug'],
       },
     ]);
   },