Remove orders length check

packages/contracts/src/2.0.0/forwarder/LibForwarderErrors.sol

@@ -31,5 +31,4 @@ contract LibForwarderErrors {
     string constant DEFAULT_FUNCTION_WETH_CONTRACT_ONLY = "DEFAULT_FUNCTION_WETH_CONTRACT_ONLY";  // Fallback function may only be used for WETH withdrawals.
     string constant INVALID_MSG_VALUE = "INVALID_MSG_VALUE";                                      // msg.value must be greater than 0.
     string constant INVALID_AMOUNT = "INVALID_AMOUNT";                                            // Amount must equal 1.
-    string constant INVALID_ORDERS_LENGTH = "INVALID_ORDERS_LENGTH";                              // Length of orders must be greater than 1.
 }

packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol

@@ -77,11 +77,6 @@ contract MixinForwarderCore is
             FillResults memory feeOrderFillResults
         )
     {
-        require(
-            orders.length > 0,
-            "INVALID_ORDERS_LENGTH"
-        );
-
         // Convert ETH to WETH.
         convertEthToWeth();
 
@@ -175,11 +170,6 @@ contract MixinForwarderCore is
             FillResults memory feeOrderFillResults
         )
     {
-        require(
-            orders.length > 0,
-            "INVALID_ORDERS_LENGTH"
-        );
-
         // Convert ETH to WETH.
         convertEthToWeth();