Gemfile in keen-0.4.2 vs Gemfile in keen-0.4.3

@@ -4,9 +4,10 @@
 
 group :development, :test do
   gem 'rake'
   gem 'rspec'
   gem 'em-http-request'
+  gem 'em-synchrony', :require => false
   gem 'webmock'
 end
 
 group :development do
   # guard cross-platform listener trick