add gamebitAdapter

contracts/SmartRoute/adapter/GambitAdapter.sol

@@ -0,0 +1,28 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+
+import {IGambit} from "../intf/IGambit.sol";
+import {IDODOAdapter} from "../intf/IDODOAdapter.sol";
+
+contract GambitAdapter is IDODOAdapter {
+
+    function _gambitSwap(address to, address pool, bytes memory moreInfo) internal {
+        (address tokenIn, address tokenOut) = abi.decode(moreInfo, (address, address));
+
+        IGambit(pool).swap(tokenIn, tokenOut, to);
+    }
+
+    function sellBase(address to, address pool, bytes memory moreInfo) external override {
+        _gambitSwap(to, pool, moreInfo);
+    }
+
+    function sellQuote(address to, address pool, bytes memory moreInfo) external override {
+        _gambitSwap(to, pool, moreInfo);
+    }
+}

contracts/SmartRoute/intf/IGambit.sol

@@ -0,0 +1,6 @@
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+interface IGambit {
+    function swap(address _tokenIn, address _tokenOut, address _receiver) external returns (uint256);
+}