Update models in demo.py (stanford-crfm#2843)

Author: yifanmai

demo.py

@@ -18,29 +18,28 @@
 
 # Make a request
 request = Request(
-    model="ai21/j2-large", model_deployment="ai21/j2-large", prompt="Life is like a box of", echo_prompt=True
+    model="openai/gpt-4o-mini-2024-07-18", prompt="Life is like a box of", echo_prompt=True
 )
 request_result: RequestResult = service.make_request(auth, request)
 print(request_result.completions[0].text)
 
 # Expect different responses for the same request but with different values for `random`.
 # Passing in the same value for `random` guarantees the same results.
-request = Request(model="ai21/j2-large", model_deployment="ai21/j2-large", prompt="Life is like a box of", random="1")
+request = Request(model="openai/gpt-4o-mini-2024-07-18", prompt="Life is like a box of", random="1")
 request_result = service.make_request(auth, request)
 print(request_result.completions[0].text)
 
 # How to get the embedding for some text
 request = Request(
     model="openai/text-embedding-ada-002",
-    model_deployment="openai/text-embedding-ada-002",
     prompt="Life is like a box of",
     embedding=True,
 )
 request_result = service.make_request(auth, request)
 print(request_result.embedding)
 
 # Tokenize
-request = TokenizationRequest(tokenizer="ai21/j1", text="Tokenize me please.")
+request = TokenizationRequest(tokenizer="openai/o200k_base", text="Tokenize me please.")
 tokenization_request_result: TokenizationRequestResult = service.tokenize(auth, request)
 print(f"Number of tokens: {len(tokenization_request_result.tokens)}")