[SPARK-2003] Fix python SparkContext example

Author: Matthew Farrellee <matt@redhat.com>

Closes #1246 from mattf/SPARK-2003 and squashes the following commits:

b12e7ca [Matthew Farrellee] [SPARK-2003] Fix python SparkContext example
(cherry picked from commit 0e0686d3ef88e024fcceafe36a0cdbb953f5aeae)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>