Add a helpful comment.

spec/lib/msf/core/exploit/http/server_spec.rb

@@ -27,6 +27,7 @@ describe Msf::Exploit::Remote::HttpServer do
     Rex::ServiceManager.stub(:start => mock_service)
   end
 
+  # Ensure the class is hooks Metasploit::Concern
   it_should_behave_like 'Metasploit::Concern.run'
 
   describe "#add_resource" do