func TestPlacesAMoveOnBoard(t *testing.T) {
board := NewBoard(rules.THREE_BY_THREE)
testBoard := make([]string, 9)
testBoard[0] = "x"
board.PlaceMove(0, "x")
assert.Equal(t, testBoard, board.Slots)
}
func TestReturnsMovesRemainingOnBoard(t *testing.T) {
board := board.NewBoard(THREE_BY_THREE)
board.PlaceMove(4, FIRST_PLAYER)
assert.Equal(t, []int{0, 1, 2, 3, 5, 6, 7, 8}, MovesAvailable(board))
}