Revert "Fix broken tests due to not passing logger through to Build.candidate"

This reverts commit 2f53b78596cddb2414c78a269510559e3826cfa0.
Properly fix Build.candidate test failures

Signed-off-by: Zachary Auerbach <zak@zaksoup.com>
Stub EM.schedule in agent_manager_spec

Without stubbing EM.schedule, the block will be executed at a later date when
EM.run is called, at which point Bhm.nats is nil, which leads to spurious
failures elsewhere (e.g. email_spec).

Signed-off-by: Zachary Auerbach <zak@zaksoup.com>