added new environment class and changed energy evaluation

error right now, going in to check
initialization of state

on AF D=1 state with 1 trotter gate to D=D_init (probably always 2) state
initialization works

energy is negative! so that is good... and also, auxiliary dimension can be much smaller
when working with 'physical' states. At least for now, which is not unlogical because I start
with a slightly entangled state.