Fixes #1556, #11615 - Remove puppet rdoc support

Puppet rdoc support has been broken for a long time. Removing it from
Foreman.

Refs #3809 - Turning on some rubocop cops

Fixes #10703 - websockify is now randomly selected

Plus updated websockify to 1.6.1 version

Fixes #10584 - Replace sort.uniq with uniq.sort

Refs #3809 - Remove useless assignments

Refs #3809 - Remove rubocop TODOs

Removed the following TODOs so that cops for these will run from now on:

Lint/AmbiguousOperator, DefEndAlignment, DeprecatedClassMethods
EnsureReturn, RequireParentheses, Void, BlockAlignment, EndAlignment,
UselessAccessModifier,...

fixes #809 - remove out of date ssh using foreman script

the script has been replaced with an hammer plugin, see:
https://github.com/theforeman/hammer-cli-foreman-ssh

fixes #5987 - remove unused packaging files

fixes #5443 - cron.log is now appended to

fixes #3983 - added trends:clean to cron