## Changes
This PR:
1. Moves the if mutator to the bundle package, to live with all-time
greats such as `bundle.Seq` and `bundle.Defer`. Also adds unit tests.
2. `bundle destroy` now returns early if `root_path` does not exist. We
do this by leveraging a `bundle.If` condition.
## Tests
Unit tests and manually.
Here's an example of what it'll look like once the bundle is destroyed.
```
➜ bundle-playground git:(master) ✗ cli bundle destroy
No active deployment found to destroy!
```
I would have added some e2e coverage for this as well, but the
`cobraTestRunner.Run()` method does not seem to return stdout/stderr
logs correctly. We can probably punt looking into it.
shreyas-goenka