GPT4All API Scaffolding. Matches OpenAI OpenAPI spec for chats and completions (#839)

* GPT4All API Scaffolding. Matches OpenAI OpenAI spec for engines, chats and completions

* Edits for docker building

* FastAPI app builds and pydantic models are accurate

* Added groovy download into dockerfile

* improved dockerfile

* Chat completions endpoint edits

* API uni test sketch

* Working example of groovy inference with open ai api

* Added lines to test

* Set default to mpt

gpt4all-api/gpt4all_api/app/tests/test_endpoints.py

@@ -0,0 +1,35 @@
+"""
+Use the OpenAI python API to test gpt4all models.
+"""
+import openai
+openai.api_base = "http://localhost:4891/v1"
+
+openai.api_key = "not needed for a local LLM"
+
+
+def test_completion():
+    model = "gpt4all-j-v1.3-groovy"
+    prompt = "Who is Michael Jordan?"
+    response = openai.Completion.create(
+        model=model,
+        prompt=prompt,
+        max_tokens=50,
+        temperature=0.28,
+        top_p=0.95,
+        n=1,
+        echo=True,
+        stream=False
+    )
+    assert len(response['choices'][0]['text']) > len(prompt)
+    print(response)
+
+# def test_chat_completions():
+#     model = "gpt4all-j-v1.3-groovy"
+#     prompt = "Who is Michael Jordan?"
+#     response = openai.ChatCompletion.create(
+#         model=model,
+#         messages=[]
+#     )
+
+
+