private void Awake()
    {
        if (!instance)
        {
            instance = this;
        }
        else
        {
            Destroy(this);
        }

        spawnTimer = spawnTimerBase;
    }
    // Use this for initialization
    void Start()
    {
        playerGO     = GameObject.FindGameObjectWithTag("Player");
        playerScript = playerGO.GetComponent <CharacterControl>();

        GM                 = GameObject.FindGameObjectWithTag("GM");
        gameOverScript     = GM.GetComponent <gameOverText>();
        spawnEnemiesScript = GM.GetComponent <spawnEnemies>();

        agent = GetComponent <NavMeshAgent>();

        startRotation = transform.rotation;

        anim = GetComponent <Animator>();

        startPos = transform.position;
        endPos   = startPos + (transform.forward * patrolDistance);
    }