Add helper method for cask installer to get dependencies.
Add helper method for cask installer to get dependencies.

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