made a robber, wrote more of play_knight_card
updated README
can play knight cards. need to redraw robber and implement move_robber() for rolling a seven
after knight card played (successfully), seem to be able to move the robber but can't get the player with settlements on the new tile's vertices so can't steal resources from them
after knight card played (successfully), seem to be able to move the robber but can't get the player with settlements on the new tile's vertices so can't steal resources from them
after knight card played (successfully), seem to be able to move the robber but can't get the player with settlements on the new tile's vertices so can't steal resources from them
rebasing 'after knight card played (successfully)... from branch new to branch master
committing this just so i can switch branches