This commit adds progress output while waiting for `depends_on`
conditions to resolve. The initial output looks like so:
⠿ Container chbench-zookeeper-1 Waiting 0s
⠿ Container chbench-kafka-1 Waiting 0s
⠿ Container chbench-one-off Waiting 0s
Once all conditions have been resolved, the ouput looks like this:
⠿ Container chbench-zookeeper-1 Healthy 1.2s
⠿ Container chbench-kafka-1 Healthy 3.2s
⠿ Container chbench-schema-registry-1 Exited 4s
As shown above, `service_healthy` conditions result in a terminal status
of "Healthy" while `service_exited_successfully` conditions result in a
terminal status of "Exited".
Signed-off-by: Nikhil Benesch <nikhil.benesch@gmail.com>