add tfa unittest from Nick
add tfa unittest from Nick

ryi06/inferelator_ng,AaronWatters/inferelator_ng,simonsfoundation/inferelator_ng,AaronWatters/inferelator_ng,simonsfoundation/inferelator_ng,AaronWatters/inferelator_ng,simonsfoundation/inferelator_ng,ryi06/inferelator_ng