Fix username and logout links position in header

The username and info links in the header look a little weird. 

They currently look like this:
- http://cl.ly/image/1X3H3U3u0C20
- http://cl.ly/image/1j3n2L1x3H3Q

This PR changes them to look like this:
- http://cl.ly/image/1P2m3D2K3p2B
- http://cl.ly/image/2Y1M3N2R103n

Also side note: The logout link doesn't appear when a user is logged in on mobile because of [this line of code](https://github.com/npm/newww/blob/master/assets/styles/_header.styl#L295). Is this the intended behavior?