Do not vendor cookbooks using Berkshelf anymore

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

cookbooks/nginx/templates/default/nginx.service.erb

@@ -1,13 +0,0 @@
-[Unit]
-Description=The nginx HTTP and reverse proxy server
-After=network.target remote-fs.target nss-lookup.target
-
-[Service]
-ExecStartPre=<%= node['nginx']['binary'] %> -t
-ExecStart=<%= node['nginx']['binary'] %>
-ExecReload=/bin/kill -s HUP $MAINPID
-ExecStop=/bin/kill -s QUIT $MAINPID
-PrivateTmp=true
-
-[Install]
-WantedBy=multi-user.target