Some possibly valid ULYSSES data types are not supported in pyspedas.ulysses.load()

[jameswilburlewis]

epac instrument: According to the CDAWeb directory layout, valid options appear to include:

'epac_br', 'epac_el', 'epac_er', 'epac_hr', 'epac_hs', 'epac_m1', 'epac_op', 'epac_oz', epac_pr', 'epac_ps', 'epac_zr', epac_zs'

but only epac_m1 seems to be supported at the moment.