small controller to deliver images

This is nice for development, but should not be used in production. Most
webservers can do better.

controller/image.rb

@@ -0,0 +1,11 @@
+module Routes
+  class Images
+    def self.call(session)
+      file = "images/#{session.request.path.gsub(/images/, '')}"
+      return RouteNotFound unless File.exist?(file)
+      session.response.body = File.read(file)
+      session.response.content_type = 'image/png'
+      nil
+    end
+  end
+end