Removes brew-cask install step, as it is deprecated

[jmftrindade]

This change fixes the maximum-awesome installation failure due to being unable to install Homebrew-cask (error message 'No available formula with the name 'brew-cask"').

As of December 2015, "brew install brew-cask" is deprecated in favor of keeping Homebrew-cask up-to-date together with Homebrew. For details, see:

https://github.com/ctran/homebrew-cask#important-december-2015-update-homebrew-cask-will-now-be-kept-up-to-date-together-with-homebrew-see-15381-for-details-if-you-havent-yet-run-brew-uninstall---force-brew-cask-brew-update-to-switch-to-the-new-system

TESTED=Confirmed that maximum-awesome install process works as expected with the proposed changes.

[asker517]

👍

[rudle]

This seems ok to me, but I can't make time to test out the results right now.

Is there any cleanup that this Rakefile should do to remove brew cask from our user's systems? In what state will a maximum-awesome user's brew system be left in after running this.

[ggilder]

@jmftrindade I don't think this will work out of the box; brew cask is still not included with homebrew by default. Per https://github.com/Homebrew/brew/blob/master/share/doc/homebrew/External-Commands.md#user-submitted-commands we still need to make sure the brew cask tap is set up using brew tap caskroom/cask.

[qtleeq]

@ggilder actually @jmftrindade is right; the lines she strikes from the Rakefile are no longer necessary and create an error.

NOTE This is the final release of Homebrew-cask. As of this release, it is no longer necessary to brew install brew-cask. brew tap caskroom/cask will install brew-cask as a Homebrew external command, and brew update will keep it up-to-date.

Taken from here:

https://github.com/caskroom/homebrew-cask/releases/tag/v0.60.0

[ggilder]

Yes, so as that note indicates, brew-cask is not installed with homebrew, but is installed when you add the tap. So we need to add the brew tap caskroom/cask command, which this PR does not do.

[ggilder]

@jmftrindade can you update this PR to run brew tap caskroom/cask instead?