Dependency Management

[alexksbr]

As the developer of one microservice in a fleet of others, I'd like some tool that can keep track of dependencies between our services. For example, I would like to easily see which services use my API (and in which version). Then, I could gather feedback from these developers.
Also, one could draw a graph of dependencies to check for circles or bottlenecks.

When adding/editing specifications, it should be possible to specify all other specifications that this specification depends on.

This feature, together with #11, can make it possible that you're notifified when one of our dependencies uploads a new spec version.

[fdw]

I think it makes sense to depend on a specific spec version, and not in general on a different service.