void Update()
    {
        locomotion.isRunning = Input.GetKeyDown(SprintKey) && jump.IsGrounded();

        locomotion.Move(new Vector2(
                            -Input.GetAxis("Vertical"),
                            Input.GetAxis("Horizontal")
                            ));

        if (Input.GetKeyDown(JumpKey))
        {
            jump.Jump();
        }
    }