Chatarena

Changes:
1. Added Pettingzoo wrapper for using pettingzoo environments. Updated dependencies
2. Updated readme
3. Bug fixes.

Changes:
1. Significantly improve agency of OpenAI ChatGPT and GPT-4 (now it is less likely to confuse its role with others').
2. Added Pettingzoo tic-tac-toe environment
3. Added examples: `prisoners_delimma` and `pettingzoo_tictactoe`
4. Fix bug when installing `pip install -e .` 30
5. Gradio Web UI default port changed to 8080

* Added Claude backend support and a new example `examples/chatgpt_claude_ai_collaboration.json`.
* UI improvements and bug fixes
* Updated README

**Full Changelog**: https://github.com/chatarena/chatarena/commits/v0.1.8