0.5.0

Added genetic programming functionality and small general improvements.

0.4.0

Changed Environment and Simulation API to be similar with Agent API:

• env.destroy() -> env.close()
• sim.end() -> sim.close()

Referenced aiomas.expose wrapper as creamas.expose wrapper so that aiomas
would not need to be imported every time when new Agent classes are created.

Simplified Simulation API:

• Removed sim.next()