Update Slack unit tests for new requirement in Review Board.
Review Request #9645 — Created Feb. 16, 2018 and submitted — Latest diff uploaded
We landed a change in Review Board that moves publish validation to the
server side, which required updating unit tests to ensure that all
review requests had assigned reviewers before publishing. This change
does that for the review requests created in Slack integration unit
tests.
Ran rbintegrations test suite.