info -> warning log (#33)

For getting notifications in the alerts-ebbo slack channel, I've changed
the current release logger to "warning", which was otherwise set to
"info".

src/off_chain/cow_endpoint_surplus.py

@@ -271,7 +271,7 @@ def logging_function(
         Logs to terminal (and file iff file_name is passed).
         """
 
-        self.logger.info(
+        self.logger.warning(
             "Transaction Hash: %s\nFor order: %s\nWinning Solver: %s\n"
             "More surplus Corresponding Solver: %s\nDeviation: %s\n"
             "absolute difference: %s\n",