Do not vendor cookbooks using Berkshelf anymore

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

cookbooks/redis/Gemfile

@@ -1,20 +0,0 @@
-source "https://rubygems.org"
-
-chef_version = ENV.fetch("CHEF_VERSION", "11.16")
-
-gem "chef", "~> #{chef_version}"
-gem "chefspec", "~> 4.1.1" if chef_version =~ /^11/
-
-gem "berkshelf", "~> 3.2.1"
-gem "foodcritic", "~> 4.0.0"
-gem "license_finder", "~> 1.2.0"
-gem "rake"
-gem "rubocop", "~> 0.27.1"
-gem "serverspec", "~> 2.3.1"
-
-group :integration do
-  gem "busser-serverspec", "~> 0.5.3"
-  gem "guard-rspec", "~> 4.3.1"
-  gem "kitchen-vagrant", "~> 0.15.0"
-  gem "test-kitchen", "~> 1.2.1"
-end