add flash trade

contracts/intf/IDODO.sol

@@ -25,9 +25,17 @@ interface IDODO {
 
     function claimOwnership() external;
 
-    function sellBaseToken(uint256 amount, uint256 minReceiveQuote) external returns (uint256);
+    function sellBaseToken(
+        uint256 amount,
+        uint256 minReceiveQuote,
+        bytes calldata data
+    ) external returns (uint256);
 
-    function buyBaseToken(uint256 amount, uint256 maxPayQuote) external returns (uint256);
+    function buyBaseToken(
+        uint256 amount,
+        uint256 maxPayQuote,
+        bytes calldata data
+    ) external returns (uint256);
 
     function querySellBaseToken(uint256 amount) external view returns (uint256 receiveQuote);
 

contracts/intf/IDODOCallee.sol

@@ -0,0 +1,18 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+interface IDODOCallee {
+    function dodoCall(
+        bool isBuyBaseToken,
+        uint256 baseAmount,
+        uint256 quoteAmount,
+        bytes calldata data
+    ) external;
+}