This is entirely fair, as your contribution and value to the company has also increased.
At the very least, the company should be paying market rates for your services. As a benchmark, median RoR guys in Boston are getting $115k > http://www.indeed.com/jobs?q=ruby+on+rails,+supervise+offsho...
How to Ask-
Understand that perceptions dominate all parts of negotiation. It's important to take the emotional temperature of your boss and deal with it. Is he happy with your performance?
On this subject, Stuart Diamond is masterful > https://www.youtube.com/watch?v=liCOqUQzpQs