Apt updates

This PR updates default newrelic settings to use ssl (to match the current settings of newrelic package).
It also updates playbook to use Ansible's native `apt_repository` module.
And finally `nrsysmond.cfg.j2` template is updated to match the current version that's in newrelic's distributed package.
I don't really want a committed out pidfile here.  I don't want people to think they should edit the file manually.  Perhaps the docs should also be wrapped in the `if` statement to hide them as well.