Update Reactive Ruby

[Malte Viering]

Hello All,

We just want to quickly announce that I finished my thesis a couple of 
months ago. In which I add some Reactive Programming features to Truffle 
Ruby.  Some more information about our work is at: 
http://guidosalva.github.io/ReactiveRubyTruffle/. The website also 
contains a link to the thesis.
Our implementation currently does not use the newest version of Truffle 
Ruby and Graal. We plan to update the code to the newest version of both 
in the near future.

Best
Malte