Link to **Python** docs of travis.

I think this make more sense, since all of these options are explained there.

Author: Thomas Güttler

docs/scenarios/ci.rst

@@ -77,7 +77,7 @@ this example content::
 This will get your project tested on all the listed Python versions by
 running the given script, and will only build the master branch. There are a
 lot more options you can enable, like notifications, before and after steps
-and much more. The `travis-ci docs <http://about.travis-ci.org/docs/>`_
+and much more. The `travis-ci docs <https://docs.travis-ci.com/user/languages/python/>`_
 explain all of these options, and are very thorough.
 
 In order to activate testing for your project, go to `the travis-ci site <https://travis-ci.org/>`_