Support for byte streams or other formats than .wav files
**Is your feature request related to a problem? Please describe.**
Using nemo toolkit in a production environment is not really an option, since you usually don't work
with files but streams, byte arrays etc. This is problematic since all classes and functions in Nemo
expect .wav files to work with.

**Describe the solution you'd like**
Change classes and functions to accept additional file formats like IOBase.

**Describe alternatives you've considered**

Rewriting the repo, but since this is a massive change it would invalidate any future versions of Nemo.

