Remove orphaned command_prompt page
Update deckrb and dependencies (required for .notes)
Add CLI presentation slides (a bit long, but it's a starting point)
Link to CLI presentation, move old page to extra credit
Fix several occurences of RailsBridge where the B was not capitalized
Add a line for finding the terminal equivalent for Chromebook (nitrous.io)

Suggested by Melissa. Can this terminal actually do all the things that
we do in the presentation? I'm not sure.
Bump Ruby version
Add more links between Downloads and Installfest pages

This will make navigating between pages a little smoother without having to
touch the main nav menu.
Merge pull request #162 from railsbridge-boston/mx-link-downloads-and-installfest

Add more links between Downloads and Installfest pages
Merge pull request #161 from railsbridge-boston/cli-slides

CLI slides
Merge pull request #159 from railsbridge-boston/2014-09-vbox-versions

Update VirtualBox and Vagrant minor versions for September workshop
Change the box name so we don't need to vagrant box remove

I am optimizing the box name here for human speech, so it's not exactly
the same as the filename. See #155.