Upgrade distros to ensure all packages are the latest
user
```ruby
def upgrade_pkgs_on_host(host, os)
  case os
  when :debian
    on host, "apt-get update"
    on host, "DEBIAN_FRONTEND=noninteractive apt-get -o Dpkg::Options::=\"--force-confnew\" --force-yes -fuy dist-upgrade"
  when :redhat
    on host, "yum clean all -y"
    on host, "yum upgrade -y"
  when :fedora
    on host, "yum clean all -y"
    on host, "yum upgrade -y"
  else
    raise ArgumentError, "Unsupported OS '#{os}'"
  end
end

step "Upgrade each host" do
  hosts.each do |host|
    upgrade_pkgs_on_host(host, test_config[:os_families][host.name])
  end
end
```
assistant