documented get_bpt and added keywords and SNR cuts
documented get_bpt and added keywords and SNR cuts

albireox/marvin,bretthandrews/marvin,bretthandrews/marvin,bretthandrews/marvin,sdss/marvin,sdss/marvin,albireox/marvin,albireox/marvin,bretthandrews/marvin,sdss/marvin,sdss/marvin,albireox/marvin