Simplified extraction of temperature and emission measure arrays from
input GOESLightCurve object in rad_loss_rate().
Changed name of rad_loss_rate() to radiative_loss_rate().
Changed name of download kwargs in radiative_loss_rate() and calc_rad_loss()
to force_download.
Further simplified extraction of temperature and emission measure
arrays from input GOESLightCurve object in radiative_loss_rate()
started 3 commits ago.  Also corrected some critical typos in that
commit.
Changed IOError at end of calc_rad_loss() to ValueError.