Release Prolific Watcher version 0.4.0-alpha.0.
Release Prolific Watcher version 0.4.0-alpha.0.

 * Upgrade `avenue` to `^0.6.8`.
 * Upgrade `destructible` to `7.0.0-alpha.38`.
 * Replace Prospective once with Eject.
 * Remove `rimraf` from `package.json`.
 * Remove `rimraf` dependency.
 * Update `LICENSE` for 2021.

Closes #1368.

bigeasy/prolific,bigeasy/prolific