for the tests to run

Index: Gemfile
--- Gemfile.orig
+++ Gemfile
@@ -20,7 +20,7 @@ group :development, :test do
   end
 
   if Gem.ruby_version >= Gem::Version.new("2.0.0")
-    gem "mime-types", "~> 1.18"
+    gem "mime-types", "~> 3.2"
   end
 
   if Gem.ruby_version >= Gem::Version.new("2.2.0")
@@ -36,8 +36,3 @@ group :development, :test do
   end
 end
 
-group :perf do
-  gem "benchmark-ips"
-  gem "patron"
-  gem "curb"
-end