Fix Homebrew on OS X El Capitan

.zshrc

function _brew () {
  for f in /usr/local/*; do
    if [ ! -w "${f}" ]; then
      echo 'Fixing /usr/local ownership...'
      sudo chown -R $(whoami):admin /usr/local
      break
    fi
  done
  brew $*
}

alias brew=_brew