Explicit licensing on textbook page

app/views/handouts/index.html.erb

@@ -46,6 +46,8 @@ all great things, this is no easy task.</p>
 	    <a class="carousel-control right" href="#myCarousel" data-slide="next">&rsaquo;</a>
 	  </div>
 
+          <p>This book is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike license</a>.  If you'd like to contribute, please <a href="https://github.com/ASCTech/mooculus/tree/master/public/textbook">see the textbook GitHub page</a>.</p>
+
 	  <p>
 
 	  </p>

app/views/layouts/application.html.erb

@@ -66,7 +66,7 @@
     <hr>
 
     <footer>
-      <p>&copy; <%= Date.today.strftime( '%Y' ) %>, <a href="/developers"><%=raw html_logo %> team</a>.  <a href="/contact">Contact us</a>.
+      <p>&copy; <%= Date.today.strftime( '%Y' ) %>, <a href="/developers"><%=raw html_logo %> team</a>.  <a href="/contact">Contact us</a>.  <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" /> All content licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>.</p>
     </footer>
   </div> <!-- /container -->