StokesFlow algorithm accepts new function for boundary conditions.
StokesFlow algorithm accepts new function for boundary conditions.


Former-commit-id: 7ef0b1ac011212a7a74e60b5c369eb89d347f593
Former-commit-id: 8193c062dec22f756ff610ce18240cfc230fb231
amdouglas/OpenPNM,amdouglas/OpenPNM,stadelmanma/OpenPNM,PMEAL/OpenPNM,TomTranter/OpenPNM