Test heroku-18 stack

* WIP: Basic work on audit

* WIP: Audit modal works

Need to get the ID search working.

* WIP: Javascript shenanigans for asset audit search

It's not clean but it works..

* Improve audit search bar

Optimise for APM!

* Filter asset audit list by never-audited

* Added cable functionality to audit form

Also improved styling

* FIX: Revert partialising of asset search

* Various UX Improvements

Also rearranged asset detail/edit to be more space efficient

* FIX: Remove assets from to-be-audited table when audited

Previously required a page reload

* Improve sample data generator

Does reversion properly and sets colours for asset statuses

* FIX: Gracefully handle 404s in audit search

* FEAT: Add buttons for some common defaults on audit form

TODO: Partialise those fragments and add them to the edit/create forms too.

* FIX: Fix asset sample data command when run alone

* FEAT: More handy buttons

* FIX: Stop quickbuttons being tab-selected

If someone's tabbing through, they won't be needing the buttons...

* FIX: Hide asset detail buttons for basic users

* FIX: Migrations

* Start tests for audit

* Some deduplication for testing code

* Improve asset audit testing

* Remember to test the tests Arona

* Potentially make modal tests more consistent

* FIX?: Up WebDriverWait timeout for modal tests

* FIX?: What about this way...

* Remake migrations

* Fix README badges to point to right branch

While I'm here eh :P

* Use aware time in audit

* Fix migrations again

* Fix for my fix...

* Modify audit exclusions to properly prevent data loss

* pep eiiiiiight

app.json

@@ -4,6 +4,7 @@
   "scripts": {
     "postdeploy": "python manage.py migrate && python manage.py generateSampleData"
   },
+  "stack": "heroku-18",
   "env": {
     "DEBUG": {
       "required": true