added brew cask functionality

[autodidacticon]

Added brew cask.

Added iterm2 as an example. Can remove if desired.

[keith]

Just my 2 cents, not really a big deal but I still have issues with cask. Also Homebrew/homebrew-cask#2534

[autodidacticon]

wrt Homebrew/homebrew-cask#2534, shall I append this to the zshrc?
export HOMEBREW_CASK_OPTS="--appdir=/Applications"

[keith]

Yep you can definitely set that. I'm definitely deferring this to others, cask just isn't for me.

[autodidacticon]

Updated script to append to zshrc to set brew cask opts

[croaky]

The current script doesn't require cask for any packages, does it?

We have https://github.com/thoughtbot/laptop/wiki, which is similar to this pull request, but we don't do a good job linking to it from the "Customize" section of the README.

What if instead of merging this into the codebase, you make any improvements to that wiki page, and then make this pull request just a doc change, adding a link to the wiki from the "Customize" section of the README?

[autodidacticon]

Put your personal customizations in ~/.laptop.local
Duh.

It seems this is already accounted for in the wiki. Thanks for the feedback. Amended PR as per comments.

[croaky]

@autodidacticon Awesome, thanks. Merged as b153d5e.