CI: add test to boot fakezod with -x and check return code

[eamsden]

CI should attempt to boot a fakezod as an integration test.

Open questions:

• Where do we get a patched king for CI to run?
• Should this run on
  • status branch merges?
  • All open PRs?
  • ready-for-review PRs?
  • reviewed PRs?

[ashelkovnykov]

Where do we get a patched king for CI to run?

This question is being resolved by @eamsden in Vere #566

I think the integration test should automatically run only on status branch merges, but there should be an on-demand test that reviewers can run / request for a given PR / branch.

[eamsden]

@urbit/runtime what do we need to do to have a prebuilt binary of vere with that functionality easily accessible to Ares CI?

[ashelkovnykov]

@eamsden Pull latest stable Vere release from urbit.org?

[eamsden]

@ashelkovnykov there's a couple of issues. The first is that that PR is not merged yet. The second is that Vere assumes that it will run with Vere as its serf, which is fine for normal operations, but is not fine in what we might call "yeoman" mode, where the user-invoked Vere simply loads the snapshot itself. This is done for several of the subcommands, for instance for ./urbit pack and ./urbit meld among others.