Update slack-beta from 3.4.0-beta1 to 3.4.0-beta2 (#7204)
Update slack-beta from 3.4.0-beta1 to 3.4.0-beta2 (#7204)


rogeriopradoj/homebrew-versions,rogeriopradoj/homebrew-versions,404NetworkError/homebrew-versions,pkq/homebrew-versions,mahori/homebrew-versions,victorpopkov/homebrew-versions,lantrix/homebrew-versions,404NetworkError/homebrew-versions,caskroom/homebrew-versions,lantrix/homebrew-versions,Ngrd/homebrew-versions,Ngrd/homebrew-versions,mahori/homebrew-cask-versions,pkq/homebrew-versions,victorpopkov/homebrew-versions,caskroom/homebrew-versions