I am trying to rotate my camera using a Quaternion in libGDX. I have a Quaternion created and being manipulated but I have no idea how to apply it to the camera, everything I've tried hasn't moved the camera at all.

Here is how I set up the rotation Quaternion:

    public void rotateX(float amount) {
        tempQuat.set(tempVector.set(1.0f, 0.0f, 0.0f), amount * MathHelper.PIOVER180);
        rotation = rotation.mul(tempQuat);
    }

    public void rotateY(float amount) {
        tempQuat.set(tempVector.set(0.0f, 1.0f, 0.0f), amount * MathHelper.PIOVER180);
        rotation = tempQuat.mul(rotation);
    }

Here is how I am trying to update the camera (Same update method as the original libGDX version but I added the part about the rotation matrix to the top):

    public void update(boolean updateFrustum) {
        float[] matrix = new float[16];
        rotation.toMatrix(matrix);
        Matrix4 m = new Matrix4();
        m.set(matrix);

        camera.view.mul(m);
        //camera.direction.mul(m).nor();
        //camera.up.mul(m).nor();

        float aspect = camera.viewportWidth / camera.viewportHeight;
        camera.projection.setToProjection(Math.abs(camera.near), Math.abs(camera.far), camera.fieldOfView, aspect);
        camera.view.setToLookAt(camera.position, tempVector.set(camera.position).add(camera.direction), camera.up);
        camera.combined.set(camera.projection);
        Matrix4.mul(camera.combined.val, camera.view.val);

        if (updateFrustum) {
            camera.invProjectionView.set(camera.combined);
            Matrix4.inv(camera.invProjectionView.val);
            camera.frustum.update(camera.invProjectionView);
        }
    }