setup: Add missing license attribute (metadata for upload to PyPI).
setup: Add missing license attribute (metadata for upload to PyPI).

kymbert/behave,hugeinc/behave-parallel,KevinMarkVI/behave-parallel,charleswhchan/behave,charleswhchan/behave,tokunbo/behave-parallel,spacediver/behave,KevinOrtman/behave,allanlewis/behave,allanlewis/behave,mzcity123/behave,Gimpneek/behave,Abdoctor/behave,benthomasson/behave,joshal/behave,Abdoctor/behave,Gimpneek/behave,joshal/behave,mzcity123/behave,KevinOrtman/behave,connorsml/behave,metaperl/behave,Gimpneek/behave,metaperl/behave,tokunbo/behave-parallel,vrutkovs/behave,jenisys/behave,jenisys/behave,vrutkovs/behave,spacediver/behave,connorsml/behave,kymbert/behave,benthomasson/behave