remove is_chat argument

evoprompt/models.py

@@ -296,7 +296,7 @@ class ChatModel:
         return reponse, history + messages, usage
 
 
-class LlamaChat(Llama, ChatModel):
+class LlamaChat(ChatModel, Llama):
 
     def _create_completion(
         self,
@@ -314,7 +314,7 @@ class LlamaChat(Llama, ChatModel):
         return response_text, usage
 
 
-class OpenAiChat(LLMModel, ChatModel):
+class OpenAiChat(ChatModel, LLMModel):
     """Queries an OpenAI model using its API."""
 
     def __init__(