Merge pull request #27 from alex-konovalov/gh-pages

Removed reference to deprecated motivation.md file

creating-lesson/index.html

@@ -293,7 +293,6 @@ <h2>Required Files</h2>
 	  <li><code>index.md</code>: lesson's home page</li>
 	  <li><code>discussion.md</code>: general discussion and pointers</li>
 	  <li><code>instructors.md</code>: instructor's guide</li>
-	  <li><code>motivation.md</code>: slideshow motivating lesson</li>
 	  <li><code>reference.md</code>: reference guide for learners</li>
 	</ul>
       </section>