ENH: added ecdf
TEST: added tests for almost all the code
STY: using `warn` function instead of manually printing `WARNING`in compute_fp
BUG: fixed 2 small typos in ifp
BUG: made lae constructor inner so as to not be overshadowed by inner
ENH: various small changes to match python
ENH: refactored lucastree.jl. Looks much better now
BUG: I was computing x_path[:, T+1] using wrong w values
ENH: made robust to scalar/array cases
ENH: P_tilde, P_check fields of AssetPrices. Makes them testable + matches python
BUG: a few small typos in optgrowth
CLN: housekeeping stuff