This test requires access to a local test site which can be upgraded.
1. Edit /mod/workshop/version.php and increase the $module->version to stimulate upgrade.
2. Rename /mod/chat to /mod/.chat to simulate a module missing from disk.
3. Go to your /mod folder and run `git clone https://github.com/skodak/moodle-mod_book.git book` to have a new module available.
4. Login as admin and go to your /admin page.
5. Check that the list of all available plugins categorized by their type is displayed.
6. Check that the status of the Workshop module is 'upgrade needed'.
7. Check that the status of the Book module is 'to be installed'.
8. Check that the status of the Chat module is 'missing from disk'.