add back get_open_interest_history() function

Author: zihao.jiang

test/test_trading_data.py

@@ -30,15 +30,15 @@ def test_open_interest_volume_strike(self):
     
     """
 
-    def test_get_open_interest_history(self):
-        print(self.TradingDataAPI.get_open_interest_history(instId='BTC-USDT-SWAP'))
-
-    def test_get_open_interest_history_with_params(self):
-        print(self.TradingDataAPI.get_open_interest_history(
-            instId='BTC-USDT-SWAP',
-            period='1H',
-            limit='50'
-        ))
+    # def test_get_open_interest_history(self):
+    #     print(self.TradingDataAPI.get_open_interest_history(instId='BTC-USDT-SWAP'))
+    #
+    # def test_get_open_interest_history_with_params(self):
+    #     print(self.TradingDataAPI.get_open_interest_history(
+    #         instId='BTC-USDT-SWAP',
+    #         period='1H',
+    #         limit='50'
+    #     ))
 
 if __name__ == "__main__":
     unittest.main()