fog 1.14.0 has been released, which relaxes the nokogiri requirement, allowing it to install a version that's no longer compatible with Ruby 1.8:

Installing nokogiri (1.6.0) 
Gem::InstallError: nokogiri requires Ruby version >= 1.9.2.

https://github.com/fog/fog#ruby-187

We should pin nokogiri, but only for Ruby 1.8. This is breaking test_develop.