Add test for foreman-maintan pr "Check server response via non-auth call"

[jameerpathan111]

Foreman-maintain PR: theforeman/foreman_maintain#261
description:

This patch reimplements hammer ping to use simple net::http
call instead of hammer. The main advantage is we can easily
skip the hammer auth setup which is not required for the call.
Another advantage is we can extend ping to pure foreman
and proxy.

Internaly the ping implementation moved to the instance feature,
related CLI option was kept for backward compatibility. The ping?
now returns true/false and the additional details such as error
message and failing services can be checked using additional
methods. Restrictions to :katello feature were removed as
the ping can query all types of instances now.