Agent Process Isolation and More!

• Isolate agents by processes instead of threads.
• Updated Documentation.
• New Environments: Battle Geese and Halite.
• Split timeout into: agent initialization, agent act, and episode duration.
• Reduced replay file size by sharing identical observations.
• Added Server Middleware.
• Configuration defaults and environment extensions.
• Training reward is now the diff between step rewards.

Bug Fixes

• ConnectX out of bounds.
• Prevent sharing state by reference to agents.
• Legend scrambled ascii characters.
• Stop storing invalid actions on replays.