Displaying Meteor.user().username using Tracker React

Hello, I am fairy new to Meteor 1.3 + React.

I have been trying to display the Username of a Logged in user using Tracker React.
I have removed the autopublish packages.

/Client/components/dashboard/sidebar.jsx

import  React, {Component} from 'react'
import TrackerReact from 'meteor/ultimatejs:tracker-react';

export default class Sidebar extends TrackerReact(Component) {

    constructor() {
        super();
        this.state = {
            subscription: {
                users: Meteor.subscribe('users')
            }
        };

    }
 render() {
        return( 
         <div>
              <h1>{Meteor.user().username}</h1>
        </div>
   );
}

/Server/publications/userPublications

Meteor.publish("users", function () {
    return Meteor.users.find();
});

I am getting a null object while console.log(Meteor.user()). However, I can see the current username using the Meteor DevTools for chrome.

What block of puzzle am I missing?