added new connector

contracts/connectors/matcha.sol

@@ -0,0 +1,124 @@
+pragma solidity ^0.6.0;
+
+// import files from common directory
+import { TokenInterface , MemoryInterface, EventInterface} from "../common/interfaces.sol";
+import { Stores } from "../common/stores.sol";
+import { DSMath } from "../common/math.sol";
+
+contract MatchaHelpers is Stores, DSMath {
+
+    /**
+     * @dev Return  1Inch Address
+     */
+    function getMatchaAddress() internal pure returns (address) {
+        return 0x61935CbDd02287B511119DDb11Aeb42F1593b7Ef;
+    }
+
+    function getWETHAddress() internal pure returns (address) {
+        return 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
+    }
+
+    function convert18ToDec(uint _dec, uint256 _amt) internal pure returns (uint256 amt) {
+        amt = (_amt / 10 ** (18 - _dec));
+    }
+
+    function convertTo18(uint _dec, uint256 _amt) internal pure returns (uint256 amt) {
+        amt = mul(_amt, 10 ** (18 - _dec));
+    }
+
+    function getTokenBal(TokenInterface token) internal view returns(uint _amt) {
+        _amt = address(token) == getEthAddr() ? address(this).balance : token.balanceOf(address(this));
+    }
+
+    function getTokensDec(TokenInterface buyAddr, TokenInterface sellAddr) internal view returns(uint buyDec, uint sellDec) {
+        buyDec = address(buyAddr) == getEthAddr() ?  18 : buyAddr.decimals();
+        sellDec = address(sellAddr) == getEthAddr() ?  18 : sellAddr.decimals();
+    }
+}
+
+// A partial WETH interfaec.
+interface IWETH is IERC20 {
+    function deposit() external payable;
+}
+
+contract Matcha {
+
+    IWETH WETH = getWETHAddress();
+
+    // Payable fallback to allow this contract to receive protocol fee refunds.
+    receive() external payable {}
+
+    // Transfer tokens held by this contrat to the sender/owner.
+    function withdrawToken(TokenInterface token, uint256 amount)
+        external
+    {
+        require(token.transfer(address(this), amount));
+    }
+
+    // Transfer ETH held by this contrat to the sender/owner.
+    function withdrawETH(uint256 amount)
+        external
+    {
+        (address(this)).transfer(amount);
+    }
+
+    function depositETH()
+        external
+        payable
+    {
+        WETH.deposit{value: msg.value}();
+    }
+    event BoughtTokens(
+        address indexed sellAddr,
+        address indexed buyAddr,
+        uint256 buyAmt,
+        uint256 setId
+    );
+ /**
+     * @dev swap ERC20_Token/ERC20_Token using Matcha.
+     * @param buyAddr buying token address.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param sellAddr selling token address.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param spender  The `allowanceTarget` field from the API response.
+     * @param swapTarget The `to` field from the API response.
+     * @param swapCallData  The `data` field from the API response.
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setId Set token amount at this ID in `InstaMemory` Contract.
+     
+    */
+    function fillQuote(
+        TokenInterface sellAddr,
+        TokenInterface buyAddr,
+        address spender,
+        address payable swapTarget,
+        bytes calldata swapCallData,
+        uint ethAmt,    
+        uint setId
+    ) external payable {
+        // Track our balance of the buyAddr to determine how much we've bought.
+        uint256 initial = getTokenBal(buyAddr);
+
+        uint buyAmt;
+
+        // Give `spender` an infinite allowance to spend this contract's `sellToken`.
+        // Note that for some tokens (e.g., USDT, KNC), you must first reset any existing
+        // allowance to 0 before being able to update it.
+        require(sellAddr.approve(spender, uint(-1)));
+        // Call the encoded swap function call on the contract at `swapTarget`,
+        // passing along any ETH attached to this function call to cover protocol fees.
+        (bool success,) = swapTarget.call.value(ethAmt)(swapCallData);
+        require(success, 'SWAP_CALL_FAILED');
+        // Refund any unspent protocol fees to the sender.
+        address(this).transfer(address(this).balance);
+
+        // Use our current buyToken balance to determine how much we've bought.
+        uint finalBal = getTokenBal(buyAddr);
+
+        buyAmt = sub(finalBal, initialBal);
+
+        setUint(setId, buyAmt);
+
+        emit BoughtTokens(sellAddr, buyAddr, boughtAmount, setId);
+    }
+
+    
+}