running tests locally complains about finding tilt library

[vegetabill]

When I checkout master and try to run rake, it gives the following error:

lib/react/jsx/template.rb:1:inrequire': cannot load such file -- tilt (LoadError)`

When I added it as a dev dependency, like this:

s.add_development_dependency 'tilt'

It worked and the tests passed.

I'm using rbenv, rake v10.4.2, ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-darwin13.0]

[rmosolgo]

addressed here #248