update requests_oauthlib

lib/requests_oauthlib/compliance_fixes/fitbit.py

@@ -8,8 +8,6 @@ MissingTokenError.
 
 from json import loads, dumps
 
-from oauthlib.common import to_unicode
-
 
 def fitbit_compliance_fix(session):
     def _missing_error(r):
@@ -17,7 +15,7 @@ def fitbit_compliance_fix(session):
         if "errors" in token:
             # Set the error to the first one we have
             token["error"] = token["errors"][0]["errorType"]
-        r._content = to_unicode(dumps(token)).encode("UTF-8")
+        r._content = dumps(token).encode()
         return r
 
     session.register_compliance_hook("access_token_response", _missing_error)