Revert "Check that the heartbeat is functioning before activating."
Reverts open-craft/opencraft#316
I too quickly merged this before testing it on stage. After testing it with https://stage.console.opencraft.com/instance/2110/edx-appserver/611/, the server failed to configure for seemingly a related reason, so I've made this revert PR. Will merge as soon as tests pass and we can try again.