trade_history should paginate through results

this avoids huge results

scripts/rest_client.py

@@ -200,13 +200,19 @@ class FtRestClient():
         """
         return self._get("logs", params={"limit": limit} if limit else 0)
 
-    def trades(self, limit=None):
-        """Return trades history.
+    def trades(self, limit=None, offset=None):
+        """Return trades history, sorted by id
 
-        :param limit: Limits trades to the X last trades. No limit to get all the trades.
+        :param limit: Limits trades to the X last trades. Max 500 trades.
+        :param offset: Offset by this amount of trades.
         :return: json object
         """
-        return self._get("trades", params={"limit": limit} if limit else 0)
+        params = {}
+        if limit:
+            params['limit'] = limit
+        if offset:
+            params['offset'] = offset
+        return self._get("trades", params)
 
     def trade(self, trade_id):
         """Return specific trade