Do not vendor cookbooks using Berkshelf anymore

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

cookbooks/nginx/attributes/headers_more.rb

@@ -1,24 +0,0 @@
-#
-# Cookbook:: nginx
-# Attributes:: headers_more
-#
-# Author:: Lucas Jandrew (<ljandrew@riotgames.com>)
-#
-# Copyright:: 2012-2017, Riot Games
-#
-# 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.
-#
-
-default['nginx']['headers_more']['version']         = '0.30'
-default['nginx']['headers_more']['source_url']      = "https://github.com/openresty/headers-more-nginx-module/archive/v#{node['nginx']['headers_more']['version']}.tar.gz"
-default['nginx']['headers_more']['source_checksum'] = '2aad309a9313c21c7c06ee4e71a39c99d4d829e31c8b3e7d76f8c964ea8047f5'