Fix Codeception license URL (Codeception#166)

* Fix Codeception license URL

* Update Codeception license URL

Because the default branch changed to 3.0.

Author: estellerostan

_layouts/bootstrap.html

@@ -243,7 +243,7 @@ <h4>Thanks to</h4>
                     <li><a href="/changelog">Releases</a></li>
                     <li><a href="http://sdclabs.com/codeception?utm_source=codeception.com&utm_medium=bottom_menu&utm_term=link&utm_campaign=reference" >Enterprise Support</a></li>
                     <li><a href="http://sdclabs.com/trainings?utm_source=codeception.com&utm_medium=bottom_menu&utm_term=link&utm_campaign=reference" >Trainings</a></li>                  
-                    <li><a href="https://github.com/Codeception/Codeception/blob/master/LICENSE">License</a></li>
+                    <li><a href="https://github.com/Codeception/Codeception/blob/3.0/LICENSE</a></li>
                 </ul>
 
 
@@ -340,4 +340,4 @@ <h4>Codeception Family</h4>
 {% include algolia.html %}
 
 </body>
-</html>
+</html>