Sodaracers Python Encoding (walk_creator & hand-designed Square, Radial, and CPPN seeds)

[mathyouf]

Done:

• The walk_creator has the add_joint, add_muscle, and get_walker methods
• get_walker serializes to the desired intermediate Sodaracer representation when called

• Walker.validate ensures the Sodaracer will not break the underlying Box2D physics engine
• square.py, radial.py, CPPN_fixed.py, and CPPN_mutable.py are instantiations of hand-designed Sodaracers, which the diff model can be applied to (copied from pg. 46-48)
• README.md added with references to the paper

To Do:

• (Optional) Check validity of serialized Seeds against Sodaracer Environment: dmahan93/pyIesorPhysics (WiP)

[herbiebradley]

Thanks, great work!