make email default NULL in download fxn #173
Description
https://github.com/ropensci/rgbif/blob/master/R/occ_download.R#L73
if user doesn't give an email mine is used, no bueno
{{ message }}
https://github.com/ropensci/rgbif/blob/master/R/occ_download.R#L73
if user doesn't give an email mine is used, no bueno