MAINT: valid email address for maintainer field
MAINT: valid email address for maintainer field

Modern twine fails when uploading to pypi, citing the lack of a valid
email address for the maintainer.  Use Google groups email address
instead of URL.

eriol/pywt,michelp/pywt,michelp/pywt,rgommers/pywt,grlee77/pywt,eriol/pywt,grlee77/pywt,michelp/pywt,rgommers/pywt,rgommers/pywt,rgommers/pywt,eriol/pywt,PyWavelets/pywt,PyWavelets/pywt