Add backwards compatibility with servers that use Snow as the weather

Author: shrianshChari

src/poke_env/environment/weather.py

@@ -37,6 +37,10 @@ def from_showdown_message(message: str):
         try:
             return Weather[message.upper()]
         except KeyError:
+            if message.upper() == "SNOW":
+                # Backwards compatibility with out-of-date PS servers that still use "snow" as the weather
+                return Weather.SNOWSCAPE
+            
             logging.getLogger("poke-env").warning(
                 "Unexpected weather '%s' received. Weather.UNKNOWN will be used "
                 "instead. If this is unexpected, please open an issue at "