Implement babyagi_agent and integrate it into multimodel role playing

[hychen-naza]

Description

Add babyagi code under camel agents, and put its its example code and testing code in corresponding folders.

Feature change:
camel/agents/babyagi_agent.py: main updates happen here. I tried to make the code style and format close to chat_agent.py and reuse its functions, which hopefully would make your review process easier.

Example File:
camel/societies/role_playing_multi_model.py: babyagi_agent and chat_agent work together, but I only changed agent initialization compare to role_playing.py
examples/ai_society/babyagi_playing.py : babyagi_agent alone to plan and solve the task

Test File:
test/agents/test_babyagi_agent.py: test babyagi_agent

Babyagi Agent works by running an infinite loop that does the following steps:
1, Pulls the first task from the task list.
2, Sends the task to the execution agent, which uses OpenAI's API to complete the task based on the context.
3, Enriches the result and stores it in Chroma.
4, Creates new tasks and reprioritizes the task list based on the objective and the result of the previous task.

Compared to role-play, which has AI user and AI assistant, Babyagi Agent gives itself instructions through task creation and solve solutions by task execution.

Motivation and Context

Why is this change required? What problem does it solve?
If it fixes an open issue, please link to the issue here.
close #186

• I have raised an issue to propose this change (required for new features and bug fixes)

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of example)

Checklist

Go over all the following points, and put an x in all the boxes that apply.
If you are unsure about any of these, don't hesitate to ask. We are here to help!

• I have read the CONTRIBUTION guide. (required)
• My change requires a change to the documentation.
• I have updated the tests accordingly. (required for a bug fix or a new feature)
• I have updated the documentation accordingly.

[Obs01ete]

Please keep this PR as a draft

[hychen-naza]

Still one error in mypy test: camel/agents/babyagi_agent.py:21: error: Cannot find implementation or library stub for module named "chromadb.utils.embedding_functions" [import].

I used # type: ignore to let mypy ignore the import missing. It works for import chromadb but fails in from chromadb.utils.embedding_functions import OpenAIEmbeddingFunction.

[lightaime]

Look good! Thanks for the fix. Left a few small comments.

[lightaime]

The output of the TaskPrioritizationAgent makes sense. 😆

original_task_prompt = "Prove the Riemann hypothesis as a high school student"

task_list = [
    "Obtain a PhD in mathematics",
    "Learn high school math",
    "Learn graduate school math",
    "Learn college math",
    "Drop out of high school",
    "Start a tech company",
]
    
Prioritized task list:
['Learn high school math', 'Learn college math', 'Learn graduate school math', 'Obtain a PhD in mathematics', 'Start a tech company', 'Drop out of high school']

[lightaime]

Thanks @hychen-naza. Did some small modifications. I think it is good to merge.

[lightaime]

@hychen-naza @Obs01ete let me know if there is any question.

[Obs01ete]

LGTM