Don't set Authorization header unless API token is provided (#167)

Resolves #164

---------

Signed-off-by: Mattt Zmuda <[email protected]>

Author: mattt

replicate/client.py

@@ -49,10 +49,12 @@ def __init__(
         self.poll_interval = float(os.environ.get("REPLICATE_POLL_INTERVAL", "0.5"))
 
         headers = {
-            "Authorization": f"Token {api_token}",
             "User-Agent": f"replicate-python/{__version__}",
         }
 
+        if api_token is not None and api_token != "":
+            headers["Authorization"] = f"Token {api_token}"
+
         transport = kwargs.pop("transport", httpx.HTTPTransport())
 
         self._client = self._build_client(