uniformization of the file names and modified these when called in other files

bilby/gw/prior.py

bilby/gw/prior_files/aligned_spins_bbh.prior

bilby/gw/prior_files/aligned_spins_bbh_tides_on.prior

bilby/gw/prior_files/aligned_spins_bns.prior

bilby/gw/prior_files/aligned_spins_bns_tides_on.prior

bilby/gw/prior_files/precessing_spins_bbh.prior

bilby/gw/prior_files/precessing_spins_bbh_tides_on.prior

bilby/gw/prior_files/precessing_spins_bns.prior

bilby/gw/prior_files/precessing_spins_bns_tides_on.prior

test/gw_prior_test.py

test/prior_files/aligned_spins_bbh.prior

test/prior_files/aligned_spins_bbh_tides_on.prior

test/prior_files/aligned_spins_bns.prior

test/prior_files/aligned_spins_bns_tides_on.prior

test/prior_files/aligned_spins_waveform_tides_on.prior

test/prior_files/precessing_spins_bbh.prior

test/prior_files/precessing_spins_bbh_tides_on.prior

test/prior_files/precessing_spins_bns.prior

test/prior_files/precessing_spins_bns_tides_on.prior

test/prior_test.py