Use latest rack-test.

Gemfile

@@ -8,7 +8,6 @@ else
   gem "arel", '~> 2.1.0'
 end
 
-gem "rack-test", :git => "git://github.com/brynary/rack-test.git"
 gem "sprockets", :git => "git://github.com/sstephenson/sprockets.git"
 
 gem "coffee-script"

actionpack/actionpack.gemspec

@@ -23,7 +23,7 @@
   s.add_dependency('builder',          '~> 3.0.0')
   s.add_dependency('i18n',             '~> 0.6.0beta1')
   s.add_dependency('rack',             '~> 1.3.0.beta')
-  s.add_dependency('rack-test',        '~> 0.5.7')
+  s.add_dependency('rack-test',        '~> 0.6.0')
   s.add_dependency('rack-mount',       '~> 0.7.2')
   s.add_dependency('sprockets',        '~> 2.0.0.beta.2')
   s.add_dependency('tzinfo',           '~> 0.3.23')