title: Homebrew cask option not recognized?
body: <p>I am following an online resource for installing two Mac utilities</p>
  <p><a href="http://www.economyofeffort.com/2014/08/11/beyond-ctrl-remap-make-that-caps-lock-key-useful/" rel="noreferrer">http://www.economyofeffort.com/2014/08/11/beyond-ctrl-remap-make-that-caps-lock-key-useful/</a></p>
  <p>Here is the pertinent section:</p>
  <blockquote>
  <p>Install both Karabiner and Seil. (Here again, if you use Homebrew
  Cask, you can do this with</p>
  <p>$ brew <strong>cask</strong> install karabiner and</p>
  <p>$ brew <strong>cask</strong> install seil</p>
  </blockquote>
  <p>But the <em>cask</em> option is not recognized?</p>
  <pre><code>06:51:35/shared $brew cask install seil
  Error: Unknown command: cask
  </code></pre>
  <p>Then, just for laughs I tried the command without the <em>cask</em>:</p>
  <pre><code>06:55:01/shared $brew install seil
  Error: No available formula for seil
  Searching formulae...
  Searching taps...
  Caskroom/cask/seil
  </code></pre>
  <p>It is not clear what the last line of output even means: nothing seems to have happened on the system.</p>
  <p>I am on Yosemite.</p>