Adapt RubyVersion spec now that it fallbacks to RUBY_ENGINE_VERSION
Adapt RubyVersion spec now that it fallbacks to RUBY_ENGINE_VERSION

* stub RUBY_ENGINE in specs, Bundler.ruby_engine no longer exists.

mvz/bundler,bundler/bundler,mvz/bundler,dilumnavanjana/bundler,bundler/bundler,dilumnavanjana/bundler