Upgrade to sourcify-0.6.0 compatibility

First of all I want to say THANK YOU for developing such a great gem. I've made benchmark comparison with other approaches to DCI implementation, including extend, PORO, SimpleDelegator etc, and maroon rocks with performance close to plain methods implementation. Would be happy to make some contribution into future development of gem.

This time, two major changes are proposed:
1. Structure and naming
Implies standard gem structure, including maroon.rb (for proper handling by rvms etc.) in root directory and snake_case file naming.

2. Sourcify-0.6.0 compatibility
New version of sourcify introduces scopes and some other great things following development of Ruby itself. Updated sourcify is now based on newer versions of sexp_processor and ruby2ruby, which should eliminate bugs of old releases (though introducing few another ones, like improper handling of empty hash {} as last parameter in the function).