Bump rails version to remove svg renderer patch (#2081)

config/initializers/action_controller_svg_renderer.rb

@@ -1,7 +0,0 @@
-# FIXME: Upstream to Rails
-Rails.application.config.after_initialize do
-  ActionController.add_renderer :svg do |svg, options|
-    self.content_type = Mime[:svg] if media_type.nil?
-    svg
-  end
-end