Mocking library

### Is your feature request related to a problem? Please describe.
Will a library ever be implemented, similar to `Moto` for aws `boto3` that developers can use to mock out the box-sdk for unit testing purposes?

### Describe the solution you'd like
The ability to create a fake box environment that the box sdk can interact with in Python. I'd like to be able to create metadata templates, folder structures, files with metadata attached, etc.

### Describe alternatives you've considered
The only alternative is having to mock out each individual http request and response for the box sdk after recording them via a tool like `vcrpy`