Gemfile in postmark-1.2.1 vs Gemfile in postmark-1.3.0

@@ -5,6 +5,7 @@
 
 group :test do
   gem 'rspec', '~> 2.14.0'
   gem 'fakeweb'
   gem 'fakeweb-matcher'
+  gem 'mime-types', '~> 1.25.1'
 end
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