setup.py: add a hashbang line
setup.py: add a hashbang line

If the executable bit is set, there should be one!

drphilmarshall/emcee,pkgw/emcee,dfm/emcee3,dfm/emcee,ipashchenko/emcee,dfm/emcee,willvousden/emcee,linan7788626/emcee,johnbachman/emcee,jellis18/emcee3,joezuntz/emcee,johnbachman/emcee,ga7g08/emcee,farr/emcee,willvousden/emcee,elkingtonmcb/emcee