Gem dependency fixes

A number of people were reporting that there were issues with the gem
dependency specifications changes we made recently. This will revert
them.

gemfiles/3.2.gemfile

@@ -8,7 +8,7 @@ gem "activerecord-jdbcsqlite3-adapter", :platforms => :jruby
 gem "rubysl", :platforms => :rbx
 gem "racc", :platforms => :rbx
 gem "pry"
-gem "rails", ">= 3.2.0"
+gem "rails", "~> 3.2.15"
 gem "paperclip", :path => "../"
 
 group :development, :test do