title: Amazon S3 path or to_file wont work
body: <p>Hey guys ive got the following code in my Model </p>
  
  <p>require 'RMagick'</p>
  
  <p>class Upload &lt; ActiveRecord::Base
      belongs_to :card</p>
  
  <pre><code>has_attached_file :photo,
                    :styles =&gt; {
                      :thumb =&gt; ["100x100", :jpg],
                      :pagesize =&gt; ["500x400", :jpg],
                    },
                    :storage =&gt; :s3,
                        :s3_credentials =&gt; "#{RAILS_ROOT}/config/s3.yml",
                        :path =&gt; ":attachment/:id/:style.:extension",
                        :bucket =&gt; 'your_deck',
                    :default_style =&gt; :pagesize
  
  attr_accessor :x1, :y1, :width, :height
  
  def update_attributes(att)
  
    scaled_img = Magick::ImageList.new(self.photo.path)
    orig_img = Magick::ImageList.new(self.photo.path(:original))
    scale = orig_img.columns.to_f / scaled_img.columns
  
    args = [ att[:x1], att[:y1], att[:width], att[:height] ]
    args = args.collect { |a| a.to_i * scale }
  
    orig_img.crop!(*args)
    orig_img.write(self.photo.path(:original))
  
    self.photo.reprocess!
    self.save
  
    super(att)
  end
  </code></pre>
  
  <p>end</p>
  
  <p>This code works offline however when on Heroku with Amazon S3 it fails to work, ive tried the code with to_file and it also wont work</p>
  
  <p>I get the following error</p>
  
  <p>can't convert Array into String</p>