Add support for Ollama, Palm, Claude-2, Cohere, Replicate Llama2 CodeLlama (100+LLMs) - using LiteLLM

[ishaan-jaff]

This PR adds support for the above mentioned LLMs using LiteLLM https://github.com/BerriAI/litellm/ LiteLLM is a lightweight package to simplify LLM API calls - use any llm as a drop in replacement for gpt-3.5-turbo.

Example

from litellm import completion

## set ENV variables
os.environ["OPENAI_API_KEY"] = "openai key"
os.environ["COHERE_API_KEY"] = "cohere key"

messages = [{ "content": "Hello, how are you?","role": "user"}]

# openai call
response = completion(model="gpt-3.5-turbo", messages=messages)

# cohere call
response = completion(model="command-nightly", messages)

# anthropic call
response = completion(model="claude-instant-1", messages=messages)

[ishaan-jaff]

@daveshap can you take a look at this when possible ?

[daveshap]

@ishaan-jaff thanks for jumping in, however we have a closed team right that is "developing in public." Please refer to https://github.com/daveshap/ACE_Framework/blob/main/contributing.md