Lots of stuff. See description

Mainly the check method now seems to function properly. This however
most likely added some bloat code and other functions need to be split
up more, like the move piece function. the printMovable has been removed
as getMovable in combination with printPositionVector should be enough.
Also I added a new rendering method which will print an empty board with
a position vector as highlited tiles, it's a lot easier to read than a
bunch of positions. The pawn also needs a separate method
getAttackableTiles as they cannot check a king by moving straight
forward. The king and check test has also been added.
TODO: Castelling and checkmate.
Also very importat: the removeBlockingStraight function seems to be
broken.
Missed a check test, added it now

Forgot to try killing the piece which checks the king to remove check
status but it works as it should