Merge pull request #657 from aaronmck/master

adjust for changes in Caskroom

macos-install.sh

@@ -70,7 +70,7 @@ brew ls --versions libmagic  | grep -q . || brew install libmagic
 
 # XQuartz is required: http://xquartz.macosforge.org/landing/
 # The easiest way is through Homebrew.
-brew tap caskroom/cask
+brew tap Caskroom/cask
 brew      ls --versions brew-cask  | grep -q . || brew install brew-cask
 brew cask ls --versions xquartz    | grep -q . || brew cask install xquartz
 brew      ls --versions cairo      | grep -q . || brew install cairo