Resource names not converted to correct format

[aivuk]

According to the Data Resource specifications https://specs.frictionlessdata.io/data-resource/#name a resource name:

MUST consist only of lowercase alphanumeric characters plus “.”, “-” and “_”.

Currently, if you provide a CKAN dataset to ckan_to_frictionless.py with a resource not following the above rule, the name will be written as it is, containing any character and not in lower case.

There are two options to solve the issue:

1. Just raise an error to the user informing about the problem
2. Convert the name to a valid one, removing invalid characters and putting in lowercase.

[aivuk]

What do you think? @amercader

[amercader]

I think we should follow the spec here and parse incoming CKAN resource names to make them adhere to the spec