RemoveReviewers API: omitempty on required reviewers field causes spurious 422s

[nagl-resourcely]

Summary

Calling RemoveReviewers when you want to only remove teams elicits a 422, due to how omitempty prevents the golang client from serializing the empty reviewers slice. This field is required on the server, so the golang client needed to send reviewers: [].

Workaround

Work around this by exploiting delete idempotency =) Just pass it a bogus username alongside real team slugs.

[gmlewis]

EDIT: Ah! I see it now.
OK, gotcha.

Would you like to create a PR to fix this issue, @nagl-resourcely ?

[nagl-resourcely]

Heh, that probably would have been faster than typing up the issue. Sure - I'll send one after the workday ends.