test-bot: cleanup old PR locks.
test-bot: cleanup old PR locks.

This is a problem on older versions of Git (such as on the Mountain Lion bot).

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