[Evaluation] Delay Container Startup

[lapplislazuli]

See #49 for how the issue looks like.
We have observed that sometimes the docker-client suffers and throws errors if too many containers are started at once.
Upstream projects (like ACR) must deal with this themselves, but this can also happen in our evaluation.

Upstream we have addressed this by giving a random sleep between 10-25 seconds at the container startup. Less might be ok.

Small note:
It could be enough to throw in this delay if there are currently no running containers. If the process is running, and there wont be things spawned at once, then the delay will just add up bloat while not adding anything to the safety