Add missing fastimage dependency

lib/paperclip/attachment.rb

@@ -1,3 +1,5 @@
+require 'fastimage'
+
 module Paperclip
   # The Attachment class manages the files for a given attachment. It saves
   # when the model saves, deletes when the model is destroyed, and processes

paperclip.gemspec

@@ -16,4 +16,6 @@ Gem::Specification.new do |s|
   s.rubyforge_project = %q{paperclip}
   s.rubygems_version = %q{1.3.1}
   s.summary = %q{File attachments as attributes for ActiveRecord}
+
+  s.add_dependency 'fastimage'
 end