Clean up brew casks

[chayim]

Warning: Cannot verify integrity of '5b804d20376f7c76f12da3f2505023b85363af501ce8bba8585a2e14f0c389c9--redis-stack-server-6.2.6-v6.catalina.x86_64.zip'.
No checksum was provided for this cask.
For your reference, the checksum is:
sha256 "8bb8201a56cf9861cb22b2bc4b7d25f2e764fd64c0891b54f956efbc1c7fbf23"
==> Installing Cask redis-stack-server
🍺 redis-stack-server was successfully installed!
==> Downloading https://s3.amazonaws.com/redisinsight.download/public/releases/2.20.0/redisst
######################################################################## 100.0%
Warning: Cannot verify integrity of '88d2d53518f33faee50a465bef83e1eac4c39b0accfde2e2e86e73e0d0ede3f7--RedisInsight-v2-app-darwin.x64.tar.gz'.
No checksum was provided for this cask.
For your reference, the checksum is:
sha256 "08b8f758533d0b44d2ddf868c740b50814373d29d3c254881534f718a8d4d61f"
==> Installing Cask redis-stack-redisinsight
==> Purging files for version 2.20.0 of Cask redis-stack-redisinsight
Error: It seems there is already an App at '/Applications/RedisInsight-v2.app'.