circle.yml: Add keep-old=1 to the webhook
circle.yml: Add keep-old=1 to the webhook

maxim-belkin/homebrew-core,rwhogg/homebrew-core,maxim-belkin/homebrew-core,LinuxbrewTestBot/homebrew-core,LinuxbrewTestBot/homebrew-core,Linuxbrew/homebrew-core,Linuxbrew/homebrew-core,rwhogg/homebrew-core