Work around JSPM mysteriously returning 503 from CI

This is meant to be temporary.

Author: elia

Diff for: lib/importmap/packager.rb

@@ -110,6 +110,8 @@ def remove_package_from_importmap(package)
     end
 
     def download_package_file(package, url)
+      return `curl -s '#{url}' > #{vendored_package_path(package)}` if url =~ /jspm.io/
+
       response = Net::HTTP.get_response(URI(url))
 
       if response.code == "200"