travis.yml: email on failure, post to Slack.
travis.yml: email on failure, post to Slack.

zmwangx/brew,EricFromCanada/brew,claui/brew,jmsundar/brew,vitorgalvao/brew,reelsense/brew,AnastasiaSulyagina/brew,maxim-belkin/brew,amar-laksh/brew_sudo,amar-laksh/brew_sudo,sjackman/homebrew,Homebrew/brew,Homebrew/brew,rwhogg/brew,gordonmcshane/homebrew,nandub/brew,muellermartin/dist,JCount/brew,toonetown/homebrew,konqui/brew,gordonmcshane/homebrew,mahori/brew,reitermarkus/brew,DomT4/brew,konqui/brew,hanxue/linuxbrew,mgrimes/brew,jmsundar/brew,maxim-belkin/brew,mahori/brew,mgrimes/brew,vitorgalvao/brew,reitermarkus/brew,reitermarkus/brew,JCount/brew,Homebrew/brew,tonyg/homebrew,MikeMcQuaid/brew,aw1621107/brew,rwhogg/brew,claui/brew,palxex/brew,toonetown/homebrew,mgrimes/brew,gordonmcshane/homebrew,amar-laksh/brew_sudo,gregory-nisbet/brew,mahori/brew,staticfloat/brew,DomT4/brew,gregory-nisbet/brew,claui/brew,Linuxbrew/brew,Linuxbrew/brew,mahori/brew,hanxue/linuxbrew,JCount/brew,reitermarkus/brew,EricFromCanada/brew,alyssais/brew,konqui/brew,sjackman/homebrew,mistydemeo/homebrew,maxim-belkin/brew,Linuxbrew/brew,AnastasiaSulyagina/brew,tonyg/homebrew,aw1621107/brew,vitorgalvao/brew,aw1621107/brew,MikeMcQuaid/brew,Linuxbrew/brew,sjackman/homebrew,muellermartin/dist,jmsundar/brew,Homebrew/brew,muellermartin/dist,AnastasiaSulyagina/brew,nandub/brew,vitorgalvao/brew,claui/brew,palxex/brew,DomT4/brew,staticfloat/brew,reelsense/brew,hanxue/linuxbrew,ilovezfs/brew,konqui/brew,staticfloat/brew,ilovezfs/brew,zmwangx/brew,bfontaine/brew,pseudocody/brew,palxex/brew,reelsense/brew,toonetown/homebrew,EricFromCanada/brew,zmwangx/brew,EricFromCanada/brew,bfontaine/brew,bfontaine/brew,nandub/brew,sjackman/homebrew,nandub/brew,gregory-nisbet/brew,DomT4/brew,MikeMcQuaid/brew,mistydemeo/homebrew,tonyg/homebrew,MikeMcQuaid/brew,pseudocody/brew,alyssais/brew,ilovezfs/brew,pseudocody/brew,mistydemeo/homebrew,alyssais/brew,rwhogg/brew,JCount/brew