Minor/cosmetic: Twitter link dead in web ui

[CarlSeiler]

In ./source/navigation.jsx Twitter link on line 29 is given as http://twitter.com/azat_co but that Twitter appears not to exist. I would change it to something else and submit, but it is unclear what's Azat's preferred account as I see http://twitter.com/azatmardan or if there are plans to open a new account at azat_co.

<NavItem eventKey={2} href="http://twitter.com/azat_co">Twitter</NavItem>