*Created by: mdpiper* These BMI functions use the `hru_x`, `hru_y`, and `hru_elev` variables in PRMS. However, there's a note on line 84 of [sm_basin.f90](src/prmslib/misc/sm_basin.f90) in the PRMS repo stating that these variables haven't been coded up yet. When they are, finish the unit tests for these BMI functions.