Is there a reason for the change from MyHelloWorld to HelloWorld? 
I believe that the HelloWorld workflow is provided with the base image https://github.com/SeqWare/vagrant/blob/develop/templates/server_setup_scripts/seqware/hello-world-workflow.sh 
That's why the tutorials in their current form refer to MyHelloWorld, so that the user does not get blocked by HelloWorld which is already installed.