First commit of ngm.  NOT COMPLETE.
Calculate utility/cons ahead of time.
Working example.  Need to add some tests/Better plotting.
Refactored as class.
docs.
Doc updates.
Placeholder for import.
Takes arbitrary scaler for input as v_0.
added alt version and some notes on it.
Potential howard improvement algorithm.
Remove k_grid. Use k_v and broadcasting.
Print feedback.
&!@* Was haveing a problem with when stuff was updating.
Removed alt. Fixed printing. Updated default values.
Fix x-axis on plots.
BUG: gen_plots function doesn't know k_v params.