Migrate away from Heroku for demo server

[ml-evs]

Heroku is dropping its free tier in November, so we probably need to find somewhere else to host the reference server deployed from this repo. Two alternatives with sufficiently generous free tiers are Fly (https://fly.io/docs/about/pricing/) and Render (https://render.com/pricing).

[JPBergsma]

Thanks for pointing this out, I have put the closing date in my agenda, so I can migrate the Heroku app for the trajectory endpoint.

[ml-evs]

November has come around quickly... @JPBergsma have you already migrated the trajectories app? If not, I can investigate moving the normal reference server to Fly?

[JPBergsma]

Sorry, I did not reply sooner, I thought I had replied already.

It would be good if you investigate the move. Fly asks for a credit card which I do not have. So perhaps Render would be the easier option for now. There are several other alternatives as well, what are the requirements we need ?

[ml-evs]

Just followed their Heroku migration guide (https://fly.io/docs/rails/getting-started/migrate-from-heroku/) and now we have https://optimade.fly.dev/, seems to work fine.

I'll keep an eye monitoring to make sure I don't get billed... and can make a PR that deploys to Fly each update to master.

[ml-evs]

After many back and forth PRs, I think the Fly deployment is now working from the CI... sometimes it only seems to work the second time, so there may be some more triaging needed after dealing with #1400.

[JPBergsma]

I have migrated my trajectory branch to render.
https://optimade-python-tools-trajectory-demo.onrender.com/v1

[ml-evs]

Looks good! Once things have settled down a bit I'll make the current Fly app under an organization and give you access.