Use lexer name compatible w/ Pygments 1.5.

Tres Seaver

2016-02-14 eee002a2b0b010834a2ebede550329dbea3b3732

Use lexer name compatible w/ Pygments 1.5.

Attempt to fix Jenkins build failures such as:
http://jenkins.pylonsproject.org/job/pyramid/1992/console.

 docs/quick_tutorial/requirements.rst

@@ -109,7 +109,7 @@

For Windows:

.. code-block:: ps1con
.. code-block:: powershell

    # Windows
    c:\> cd \