Working Slurm cluster with test job execution

- Fix MUNGE key generation and distribution
- Slurm config using easy version of the config tool
- Ensure JOIN_TIMEOUT is passed to the provisioning script
- Execute hostname command as Slurm job for verification

Vagrantfile

@@ -51,6 +51,7 @@ Vagrant.configure(2) do |vm_config|
 
       # Install and Setup Slurm
       config.vm.provision "shell", inline: <<-SHELL
+        export JOIN_TIMEOUT=#{JOIN_TIMEOUT}
         /bin/bash /vagrant/provision.sh
       SHELL
     end