Update emacs-pretest to 26.1-rc1 (#5570)
Update emacs-pretest to 26.1-rc1 (#5570)


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