Do not vendor cookbooks using Berkshelf anymore

Instead, use the Berkshelf support in knife-solo and the
vagrant-berkshelf plugin on Vagrant

cookbooks/redis/Guardfile

@@ -1,5 +0,0 @@
-guard :rspec, cmd: "rspec --color", all_on_start: false do
-  watch(/^spec\/(.+)_spec\.rb$/)
-  watch(/^recipes\/(.+)\.rb$/) { |m| "spec/#{m[1]}_spec.rb" }
-  watch("spec/spec_helper.rb") { "spec" }
-end