remove dead code
add find_jail to board
add find_go to board
use find_go in lib
use find_jail in lib
use find_jail and find_go in step definitions
use mortgage rate in test

when changing the mortgage rate from 90% to 50% nothing else should need to be modified
make mortgage payback dependent on mortgage rate
clarifiction: 3rd double

after the 3rd double in a row the turn is not played.
Instead the player goes direct into jail.
switch to Cucumber::Ast::Table#hashes

before #raw was used, #hashes fits better
cleanup