The older version of Bundler (1.3.5) used on Ubuntu 14.04 is failing to find a compatible version of fog-google due to the two slightly different requirements in bundler.d/gce.rb and fog's gemspec:

08:38:16 /usr/bin/ruby2.0 /usr/bin/bundle pack --all
08:38:18 Fetching gem metadata from https://rubygems.org/........
08:38:31 Fetching gem metadata from https://rubygems.org/..
08:38:32 Resolving dependencies................
08:38:33 Bundler could not find compatible versions for gem "fog-google":
08:38:33   In Gemfile:
08:38:33     fog (= 1.38.0) ruby depends on
08:38:33       fog-google (<= 0.1.0) ruby
08:38:33 
08:38:33     fog-google (0.3.2)

The bundler.d/gce.rb specification should just mirror fog's for now for consistency. When fog changes it and we update fog, bundler.d/gce.rb can be updated in sync.