add test for `brew cask --cache`
add test for `brew cask --cache`

mahori/brew,EricFromCanada/brew,claui/brew,nandub/brew,claui/brew,reitermarkus/brew,JCount/brew,Homebrew/brew,claui/brew,EricFromCanada/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,reitermarkus/brew,nandub/brew,claui/brew,konqui/brew,nandub/brew,sjackman/homebrew,EricFromCanada/brew,reitermarkus/brew,konqui/brew,Homebrew/brew,vitorgalvao/brew,sjackman/homebrew,vitorgalvao/brew,konqui/brew,mahori/brew,nandub/brew,mahori/brew,konqui/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,reitermarkus/brew,mahori/brew,sjackman/homebrew,Homebrew/brew,vitorgalvao/brew,sjackman/homebrew,JCount/brew,vitorgalvao/brew,JCount/brew,JCount/brew,Homebrew/brew,EricFromCanada/brew