Support .depends.yaml file

**Is your feature request related to a problem? Please describe.**

In order to manage remote dependencies, and make it convenient. We want to support a .depends file that a DeployBoard job can read this file from the source repo, or maybe the file is passed along in a post request, and DeployBoard will check the dependencies and create the dependency mapping. We can throw back an error if we find a circular dependency. This is useful because tools that observe traffic like NewRelic, DataDog, etc, can map this, but these tools are after the fact. So you may already deploy to production before finding out you have a circular dependency. By using This feature of DeployBoard, you can find out during commit, PR open (preventing merges), or even pre-commit using a cli tool (to be developed).

**Describe the solution you'd like**

TBD.

**Describe alternatives you've considered**

None

**Additional context**

The .depends.yaml filename is up for debate. Maybe we can also support a .json filetype.
Should be supported via tools like Tox.