Changed input and output arrays of goes_chianti_tem(),
_get_goes_chianti_temp(), and _get_goes_chianti_em() to astropy
Quantities.
Changed temperature, emission measure and radiative loss rate input
and output arrays in calc_rad_loss() to astropy Quantities.  This has
not yet been tested though.
Fixed bug in getting time difference in seconds between measurement
times in calc_rad_loss().
Fixed typos in calling trapz and cumtrapz integrate functions.
Fixed bug in getting time difference in seconds between measurement
times is goes_lx().
Fixed typos in calling trapz and cumtrapz integrate functions in goes_lx().
Changed input and output arrays/values in goes_lx() and _calc_xraylum()
to astropy Quantities.