Change character's Y rotation based on velocity.

I'm making a top down puzzle game. You can move the character up down left and right. The character is moved by changing its velocity (rigidbody.velocity = movement). The only thing I need to do now is rotate him, I've tried LookAt, LookRotation, transform.rotation and SetLookRotation but they all seem to bug out or just not work at all. I just want the characters Y rotation to change based on its velocity, if its moving up, then rotate his Y in that direction.

My Code: public float speed = 6f; public GameObject camTarget;

     Vector3 movement; 
     Rigidbody playerRigidbody;
 
 
     void Awake(){
         playerRigidbody = GetComponent<Rigidbody> ();
     }
 
 
     void FixedUpdate(){
 
         if(Input.GetKeyDown(KeyCode.E)){
             CameraShake();
         }
 
         float h = Input.GetAxisRaw ("Horizontal");
         float v = Input.GetAxisRaw ("Vertical");
 
         Move (h, v);
     }
 
 
     void Move(float h, float v){
         movement.Set (h, 0f, v);
 
         movement = movement.normalized * speed * Time.deltaTime;
 
         playerRigidbody.velocity = movement;
 
     }
 
     
     void CameraShake(){
         Camera.main.transform.GetComponent<Animation> ().Play ("CameraDarken");
         camTarget.GetComponent<Animation> ().Play ("CameraShake");
     }

My Character:

Any help at all would be greatly appreciated.