Use forked Ferrum library until upstream accepts our patches

We need to expose the mobile setting in the Ferrum API as well. Until
that's merged, use a fork of Ferrum that exposes it.

Author: duncan-bayne

Gemfile

@@ -4,6 +4,7 @@ source "https://rubygems.org"
 
 gem "byebug", "~> 11.1", platforms: %i[mri mingw x64_mingw]
 gem "chunky_png", "~> 1.4"
+gem "ferrum", github: "radiopaedia/ferrum", branch: "94-expose-mobile"
 gem "image_size", "~> 3.0"
 gem "launchy", "~> 2.5"
 gem "pdf-reader", "~> 2.12"

lib/capybara/cuprite/page.rb

@@ -144,7 +144,7 @@ def prepare_page
         super
 
         width, height = @options.window_size
-        resize(width: width, height: height)
+        resize(width: width, height: height, mobile: @options.mobile)
 
         if @options.url_blacklist.any?
           network.blacklist = @options.url_blacklist