(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)
Whoops, didn't see that. It's not grouped with the rest of the 1.8 workarounds ;)