various tweaks

Hello

I did the following:
* Updated Twitter bootstrap css version.
* Updated Twitter bootstrap js version.
* Updated font awesome css version.
* Change github icon to be `icon-github` i.e. font rather than image - this is because font awesome's css follows bootstrap, it overrides the declaration and doesn't use the Glyphs (yay).
This icon also is closer to the new Github branding.
* Replaced Twitter bootstrap with a [Bootswtach version](http://bootswatch.com), tl;dr Vanilla bootstrap with customised `variables.less` and some other layout tweaks. This is a drop-in replacement and lives on the same CDN.

__Changing Bootswatch schemes:__
https://github.com/rjocoleman/site/blob/e9904d184c988953bd5e1ac53af23a379214b2a6/index.html#L6 to match a value from http://www.bootstrapcdn.com/#tab_bootswatch
(IMO the screenshots provided do not do these justice).

_To do geeking_ you could include a version of bootstrap without the glyph icons as you're using font awesome instead. However, despite http://blog.netdna.com/opensource/bootstrapcdn/bootswatch-no-icons-version/, updated versions of these these are not available precompiled and hosted on BootstrapCDN so you'd need to [manually build the less files](https://github.com/thomaspark/bootswatch/#customization) and include them in this repo.

It's my opinion that ordering the CSS files as I have done gives an acceptable solution, I would only go down the _geeking_ route if customising `variables.less` for a unique colour scheme (etc).