Great plugin ... I use it to dynamically update the chart here: http://www.currentinspiration.com/personal-development-2/5-qualities-of-a-good-wife/
I am adding new users to this website with a contribute role (+ ability to add media).
This user permission level is able to access Visualizer from the backend menu and can delete my graphs.
How do I change the permissions level in the plugin to prevent access from contributors (or at least hide from the menu)?