Include `__version__` in package

[sdatkinson]

Currently,

from auraloss import __version__

isn't supported.

It'd be great to have __version__ defined so that depending code can detect which version is installed and react accordingly (e.g. when APIs change).

neural-amp-modeler implements this with a _version.py (to keep DRY); I'd be happy to PR something similar if you're interested.

Cheers!

[csteinmetz1]

Thanks for raising this @sdatkinson. Sounds like a good idea. Happy to accept a PR on this.