(QENG-104) Remove gems that were pinned for Ruby 1.8

We no longer use ruby 1.8 internally. There is no reason to keep it
around any longer.

![nuke the entire site from orbit](http://iruntheinternet.com/lulzdump/images/gifs/alien-sigourneyweaver-nuke-riley-orbit-1348491814r.gif)
We might also want to clean up things like this if we're going to remove Ruby 1.8 support :)