Correct puppet module list check in beaker

The final check during the prep stage, where `puppet module list` is
run so that its output can be used for debugging, should run on the
current host in the loop, not the first host in the array.

Change-Id: Iae34f41d56d01865b08a09d4de2ec3b86ce4ce82

spec/spec_helper_acceptance.rb

@@ -35,7 +35,7 @@ RSpec.configure do |c|
       # Install the module being tested
       puppet_module_install(:source => proj_root, :module_name => 'openstacklib')
       # List modules installed to help with debugging
-      on hosts[0], puppet('module','list'), { :acceptable_exit_codes => 0 }
+      on host, puppet('module','list'), { :acceptable_exit_codes => 0 }
     end
   end
 end