Update the copyright date in footer

Creating issue to update the Butler copyright `<p class="styleguide-copyright">Copyright (c) 2016 Palantir.net</p>` to 2017.

<img width="364" alt="screen shot 2017-07-19 at 11 16 35 am" src="https://user-images.githubusercontent.com/1793999/28374974-49f57e1e-6c74-11e7-98ca-a9b276668b1e.png">
