Add RMagick gem and initial version of CarrierWave's uploader.

app/uploaders/avatar_uploader.rb

@@ -0,0 +1,55 @@
+# encoding: utf-8
+
+class AvatarUploader < CarrierWave::Uploader::Base
+
+  # Include RMagick or MiniMagick support:
+  # include CarrierWave::RMagick
+  # include CarrierWave::MiniMagick
+
+  # Include the Sprockets helpers for Rails 3.1+ asset pipeline compatibility:
+  # include Sprockets::Helpers::RailsHelper
+  # include Sprockets::Helpers::IsolatedHelper
+
+  # Choose what kind of storage to use for this uploader:
+  storage :file
+  # storage :fog
+
+  # Override the directory where uploaded files will be stored.
+  # This is a sensible default for uploaders that are meant to be mounted:
+  def store_dir
+    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
+  end
+
+  # Provide a default URL as a default if there hasn't been a file uploaded:
+  # def default_url
+  #   # For Rails 3.1+ asset pipeline compatibility:
+  #   # asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
+  #
+  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
+  # end
+
+  # Process files as they are uploaded:
+  # process :scale => [200, 300]
+  #
+  # def scale(width, height)
+  #   # do something
+  # end
+
+  # Create different versions of your uploaded files:
+  # version :thumb do
+  #   process :scale => [50, 50]
+  # end
+
+  # Add a white list of extensions which are allowed to be uploaded.
+  # For images you might use something like this:
+  # def extension_white_list
+  #   %w(jpg jpeg gif png)
+  # end
+
+  # Override the filename of the uploaded files:
+  # Avoid using model.id or version_name here, see uploader/store.rb for details.
+  # def filename
+  #   "something.jpg" if original_filename
+  # end
+
+end