Speed up cluster boot

[slominskir]

Bringing up the entire set of services (containers) quickly is important and it would be fastest to allow all containers to initialize in parallel. However, we currently use coarse healthchecks to wait before starting containers as this is simplest way to ensure services initialize without timeout. We could use a more sophisticated approach where all containers boot simultaneously but wait on dependencies in a more fine grain and flexible way.

Related: JeffersonLab/jaws-web#29