(actions): add unit test

[anik120]

No description provided.

[everettraven]

Based on #29 (review) && #29 (comment) are we okay with just adding the unit test workflow or should we supersede this PR with a new PR that implements the matrix style workflow?

[anik120]

My opinion is that we should go ahead and add the unit test action right now. Once #34 is in we'll be in a position to write some test cases for the CatalogSource reconciler that should be useful even when we're making the switch for the child resources/moving to aggregated api etc etc. Also feels like the right time to get at least the initial set of tests written down. So we can add the action, and then discuss the "matrix style tests"

I'll also need more clarification about the meaning of "matrix style tests", unless that means "rename sanity.yaml to test.yaml and add the unit test job to that file", in which I'm happy to do that in this PR

[everettraven]

/lgtm