Updated "The Team" link to point to devdocs

This is intended to be merged along side astropy/astropy#775 .  It adjusts the "The Team" link to point to the astropy (dev) docs author list instead of having a parallel one.  The idea is that this way we only need to keep one list up-to-date.

Two questions about this:

1. Right now it's pointed to the latest/development docs.  It would be a trivial change to instead have it use the list from the latest *released* version.  I mildly prefer the dev version, because it's the most up-to-date.
2. Click the "The Team" link now means that the top header changes to match the astropy docs instead of the header for the page.  This is not a big deal because the style is similar, but it's marginally jarring.  Is there any way to use the webpage css with the doc page content? (Or is that violating some important security sandboxing?)

@astrofrog @kbarbary