An idea to consider

The yaml file acts as an alias for a list of shell commands.

So given this .denv.yaml:
```yaml
vagrant:
  init:
    - git clone [repo]
  up:
    - cd [repo]
    - vagrant up
```
One can use `denv init` and the repo specified in the yaml file will be cloned into the current directory.

And `denv up` would cd into that directory and run vagrant up.

Thoughts?