Update completions_streaming.py

- random model selection is faulty - setting to a fixed instruct model

examples/completions_streaming.py

@@ -16,7 +16,7 @@
 async def main() -> None:
     client = AsyncClient()
 
-    print("Supported models:")
+    print("Available models:")
     res = await client.models.list()
     for model in res.models:
         print(model.id)
@@ -27,7 +27,7 @@ async def main() -> None:
     print(f"> {prompt}")
     try:
         stream_res = await client.completions.create(
-            model=random.choice(res.models).id,
+            model="palmyra-x-002-instruct",
             prompt=prompt,
             stream=True,
             max_tokens=64,
@@ -36,7 +36,7 @@ async def main() -> None:
             async for response in stream_res:
                 print(f"< {response.value}")
 
-    except BadRequestError as e:
+    except Exception as e:
         print(f"Error: {e.body}")