Remove old `jenkins-test` fixture cookbook (no longer used)
Update authors and copyrights
Remove Apache, Nginx, and IPTables recipes and associated files

In order to better control the scope of this cookbook, HTTP proxying and
firewall rules have been removed. Users wishing to use Jenkins behind an HTTP
proxy may choose their web server, configuration, and setup independently of
this cookbook.

This commit also removes the cookbook's dependencies on those cookbooks, any
referencing attributes, and any referencing files.