Fix DOC strings for

• TensorflowPredictVGGish
• TensorflowPredictMusiCNN

https://www.python.org/dev/peps/pep-0257/ lists some conventions how dostrings should be formatted. Most of the docstrings are compatible already, some are not.

Some are descriptive which violate the rule that a docstring should prescribe the function or method's effect as a command "Do this", "Return that", instead of "Returns the pathname ...".

sklearn issued warning message for passing attributes to check_is_fitted as follows:

FutureWarning: Passing attributes to check_is_fitted is deprecated and will be removed in 0.23. The attributes argument is ignored.
"argument is ignored.", FutureWarning)

The sklearn version that issued this warning: 0.22

Ways to reproduce:

1. Use the package version above
2. Run f0 estimatio

phdoerfler/Strugatzki@6d689a0