enable csv response format

Author: nebulon42

overpass/api.py

@@ -44,7 +44,7 @@ def Get(self, query, responseformat="geojson", verbosity="body"):
         # Get the response from Overpass
         raw_response = self._GetFromOverpass(full_query)
 
-        if responseformat == "xml":
+        if responseformat == "xml" or responseformat.startswith("csv"):
             return raw_response
 
         response = json.loads(raw_response)