Motivating example:

• User installs module A v1.0.0, which depends on module B
• User updates to module A v2.0.0, which doesn't have any dependencies
• After the update, a new version of module A code is loaded. Module B code and data linger on the user system by default

The module developers can always uninstall module B in an update step, but it should be done automatically.

Dev Notes:

• One option for implementing this: within the update command logic, we could consider running the clean lifecycle phase of the existing module before installing the new version
• Consider how to propagate a -purge flag to the correct module to uninstall (which removes data associated with the module), if it is passed to the update command