Managed dependencies support

[kidpollo]

I came accross this porblem trying to use managed dependencies in a project that already has lein npm on it. It should be as simple as this.

[RyanMcG]

To be honest, this change is a bit over my head, but it looks reasonable enough.

Do we need to bump the version of cemerick.pomegranate.aether to accept the :managed-coordinates param?

[kidpollo]

No, I dont even think that is adepenency in this project. Isnt it a transient dep from lein ? https://github.com/clj-commons/pomegranate/blob/master/CHANGES.md

[RyanMcG]

Sounds good.