The new version of Salt ("3000") seems to have a number of bugs,
including not being able to handle "unless" checks, which the Tildes
states use frequently. Because of this, creating a new dev environment
currently doesn't work. This pins Salt to the previous stable version
for now.
Here's the relevant bug for "unless" specifically:
https://github.com/saltstack/salt/issues/56131
And the overall release notes:
https://docs.saltstack.com/en/latest/topics/releases/3000.html
Without setting any defaults, it seems to give 1024MB of memory and 2
CPUs. That low of memory can (and does) result in the VM swapping itself
to death when doing some things. I'm going to set a reasonable amount in
the Vagrantfile, and update the docs to explain how to raise/lower it if
necessary (and recommend a minimum).
