DOC/CI: Fix automatic website deployments

[bocklund]

We were using TravisCI to deploy the website from our website branch to our AWS bucket, but TravisCI is no longer building on the dot-org domain and our docs aren't getting deployed anymore.

We should switch over the deployment script to GitHub Actions. AWS has an Action to configure the credentials with some Usage instructions to deploy to an S3 bucket.

[richardotis]

Fixed by 87b58fd
I also turned the Travis integration off for the pycalphad organization. It's suspended so it can be turned back on quickly if needed, but after a few days I'll probably remove it permanently. I also took the liberty of disabling some stale third-party integrations (which can also be turned back on if needed).

[richardotis]

An important aspect of the aws sync command is that it decides if a file is new by comparing timestamps. In a CI environment all the files in the website branch always have fresh timestamps, so they will all be uploaded, every commit. It's not a huge deal, but it's a little wasteful. Solutions are:

1. Add the --size-only argument, which switches it to compare file sizes instead. It solves the problem but now you risk failing to upload a change (!), if the file size was somehow unchanged. Unfortunately hash-based comparison is not supported.
2. Modify the arguments to only sync docs/latest instead of the entire docs directory
3. Some sort of trickery with git diff to enumerate the changed files. I can imagine edge cases which could also lead to upload failures / un-synced files.
4. Do nothing, bandwidth is cheap.

My current thinking is Option 2 is probably the way to go, as it's basically the same behavior as the Travis-based approach. If we need to sync other directories, it'd be pretty easy to make further changes.

[bocklund]

Option 2 sounds fine to me. Right we haven't been building tagged versions for awhile anyway. We could set up another action that is triggered on tags to build, commit, and upload a docs/<tag> directory.

[richardotis]

The changes I implemented haven't actually been working: https://github.community/t/push-from-action-does-not-trigger-subsequent-action/16854/5
I didn't notice at first because I set everything up with manual pushes, which still work (and I just triggered to ensure the latest examples are updated). This may be a good jumping off point to move forward (per our offline discussion) on splitting the website off into a separate repo, and maybe a move to an actual CMS or static-site generator.

[bocklund]

Can be triggered by pushing an empty commit to the website branch:

git commit --allow-empty -m "Bump website to trigger deployment"