updating collision handler for pymunk 5.3.2

[pythony]

My instructor's version had either add_collision_handler or add_default_collision_handler, so I believe these will work in its place.

set_default_collision_handler, and add_collision_handler are also on the older documentation
http://www.pymunk.org/en/pymunk-4.0.0/pymunk.html

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The set_default_collision_handler from 4.0.0 documentation seems to accept quite a few parameters versus the add_default_collision_handler from the 5.3.2 documentation however..