Dependency `stringcase` seems to be unmaintained

[pierrecamilleri]

Context

Frictionless has stringcase as a dependency.

From what I can see, it is used for conversion of strings to snakecase or camelcase.

Issue

The stringcase dependency seems not maintained anymore.

It triggers for instance DepreciationWarnings :

python3.9/site-packages/stringcase.py:247: DeprecationWarning: invalid escape sequence \W
return re.sub("\W+", "", string)

Proposition

I would either remove the dependency and include all code to perform this in frictionless-py, or use the Casefy alternative replacement of this library.

Do you have a preferred option? I can propose a Pull Request.