Update with 'brew upgrade --greedy' results in installing another cask with same name

[Egor Egorov]

STR:

1. brew install hkamran80/things/squirrel
2. brew upgrade --no-quarantine --greedy

Outputs:

==> Downloading https://github.com/aheze/Squirrel/releases/download/1.0.0/Squirrel.zip
Already downloaded: /Users/egigoka/Library/Caches/Homebrew/downloads/80457f17a48c2da0cdcf7f1863e841cb60446301e520041281c338bf8742e07e--Squirrel.zip
==> Installing Cask squirrel
==> Moving App 'Squirrel.app' to '/Applications/Squirrel.app'
🍺  squirrel was successfully installed!

==> Upgrading 1 outdated package:
squirrel 1.0.0 -> 0.16.1
==> Upgrading squirrel
==> Downloading https://github.com/rime/squirrel/releases/download/0.16.1/Squirrel-0.16.1.zip
Already downloaded: /Users/egigoka/Library/Caches/Homebrew/downloads/433bd3348d17419a136d01b6bb525a546ecaadd082a9a1b3d24474554ef2c3ce--Squirrel-0.16.1.zip
==> Backing App 'Squirrel.app' up to '/opt/homebrew/Caskroom/squirrel/1.0.0/Squirrel.app'
==> Removing App '/Applications/Squirrel.app'
==> Running installer for squirrel; your password may be necessary.
Package installers may write to any location; options such as `--appdir` are ignored.
installer: Package name is Squirrel
installer: Installing at base path /
installer: The install was successful.
installer: The install requires logging out now.
==> Purging files for version 1.0.0 of Cask squirrel
🍺  squirrel was successfully upgraded!

[H. Kamran]

I'll change the cask name to avoid this