Add openbolt acceptance test

[bastelfreak]

No description provided.

[ekohl]

Perhaps first introduce a shared example in its own commit? I suspect the following in spec/support/acceptance/examples.rb works.

shared_examples 'with feature' do |feature|
  let(:feature) { feature }

  cert_dir = '/etc/foreman-proxy'
  describe curl_command("https://#{host_inventory['fqdn']}:8443/features", cacert: "#{cert_dir}/certificate.pem", cert: "#{cert_dir}/certificate.pem", key: "#{cert_dir}/key.pem") do
    its(:stdout) { should include(feature) }
    its(:exit_status) { should eq 0 }
  end
end

Then you can build on that in openbolt.

[ekohl]

It probably doesn't matter a lot, but I wonder if include is semantically better.

Suggested change

	its(:stdout) { should match('discovery') }
	its(:stdout) { should include('discovery') }

[ekohl]

I submitted that in #888 because I wanted to see if it worked.

[bastelfreak]

I cherry-picked your shared example and just applied it to openvox for now, so CI can pass