Merge pull request #2260 from rspec/fix-rack-warning

Get rid of rack warning

Author: pirj

Gemfile-rails-dependencies

@@ -1,4 +1,10 @@
 version_file = File.expand_path("../.rails-version", __FILE__)
+
+# FIXME: rack 2.1.0 introduces a deprecation warning that rails is triggering,
+# but in later versions this warning will be removed. Get rid of this hack once
+# rack 2.1.0+ is out.
+gem 'rack', '!= 2.1.0'
+
 case version = ENV['RAILS_VERSION'] || (File.exist?(version_file) && File.read(version_file).chomp) || ''
 when /master/
   gem "rails", :git => "https://github.com/rails/rails.git"