Gemfile in message-driver-0.2.1 vs Gemfile in message-driver-0.2.2

@@ -1,17 +1,24 @@
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in message-driver.gemspec
 gemspec
 
+platform :rbx do
+  gem 'rubysl'
+end
+
 group :tools do
   gem 'guard'
   gem 'guard-bundler'
   gem 'guard-rspec'
   gem 'guard-cucumber'
   gem 'pry'
-  platform :ruby do
+  platform :ruby_19 do
     gem 'pry-debugger'
+  end
+  platform :ruby_20 do
+    gem 'pry-byebug'
   end
   group :darwin do
     gem 'ruby_gntp'
     gem 'rb-fsevent'
     gem 'relish'