Fixes from demonstrations in January 2023

[ksnavely]

• [x] Tick to sign-off your agreement to the Developer Certificate of Origin (DCO) 1.1

What

In this pull request I seek to make the demo runnable again.

1. The World Clock API is depreciated. Use a GitHub API which can be accessed easily and should be fairly stable.
2. I suspect binary evidence support was broken when agent-mode was added. I tweaked a conditional to restore support for signed binary evidence.

Why

To better evangelize Auditree I want the demo working well.

How

• Update the world clock example to use the GitHub versions endpoint
• Don't attempt to encode already-bytes data

Test

The demo is working, both the fetch step and the check step. Unit tests are passing.

Context

Try the demo off main today to see the failures. Linting and tests pass locally.

[ksnavely]

I'm accepting comments on this PR. I think a new test covering binary signed evidence would be a last change worth including -- it should fail off main today and pass on my branch.

[drsm79]

Thanks for this, the change looks good from a quick eyeball. One thing, calling out to the API was a nice part of the demo, as it shows the whole collect remote responses. Obviously that needs to be a working API, maybe calling a GitHub api/URL for this project would be a good additional demo?

[ksnavely]

@drsm79 I've added a GitHub API example -- what do you think of using the versions API?

[drsm79]

@drsm79 I've added a GitHub API example -- what do you think of using the versions API?

Nice, good choice.

[ksnavely]

I've added a binary signing test that now passes but fails on main.

[cletomartin]

@ksnavely perhaps we should merge #144 this first as it will fix some problems with the current CI config.

[ksnavely]

I should be good to go after you merge your PR @cletomartin , I can't recall if I'll need to re-push this branch after an update or not.

[cletomartin]

Yeah, there is some conflicts in there after my merge of #144