Vendor the external cookbooks

Knife-Zero doesn't include Berkshelf support, so vendoring everything in
the repo is convenient again

cookbooks/ntp/libraries/ntp_helper.rb

@@ -0,0 +1,49 @@
+#
+# Author:: Julian C. Dunn (<jdunn@chef.io>)
+# Cookbook:: ntp
+# Library:: helper
+#
+# Copyright:: 2014-2017, Chef Software, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require 'chef/mixin/shell_out'
+
+module Opscode
+  module Ntp
+    # Helper methods for ntp
+    module Helper
+      include Chef::Mixin::ShellOut
+
+      def ntpd_supports_native_leapfiles
+        ntpd_version = determine_ntpd_version
+        if ntpd_version
+          ntpd_version =~ /ntpd.*(\d+\.\d+\.\d+)/
+          # Abuse of Gem::Requirement, but it works
+          Gem::Requirement.new('>= 4.2.6').satisfied_by?(Gem::Version.new(Regexp.last_match(1)))
+        else
+          false
+        end
+      end
+
+      private
+
+      def determine_ntpd_version
+        cmd = shell_out!('ntpd --version 2>&1')
+        cmd.stdout.strip
+      rescue Errno::ENOENT, Mixlib::ShellOut::ShellCommandFailed
+        nil
+      end
+    end
+  end
+end