- the file.extract_hash function does not support Windows path format

I use 'file.managed' state on Windows with 'source' parameter set to external HTTP URL and I need to pass 'source_hash' parameter to verify it. The current code of the module does not seem to support Windows path format. I simply replaced 'file_name' extraction by 're.findall' function with more multi-platform 'os.path.basename' function.