Merge branch 'refactor/check-revert-reasons' into feature/combinatorial-testing

* refactor/check-revert-reasons:
  Temporarily switch revert reasons to `TransferFailed`. Should be `InvalidAmount` but because of an oversight in the assembly implementation of `dispatchTransferFrom`, it always throws `TransferFailed`
  Expect RevertReason be passed in, not string
  Rename RevertReasons to RevertReason since singular enum names are more common

# Conflicts:
#	packages/contracts/test/asset_proxy/proxies.ts
#	packages/contracts/test/exchange/core.ts

packages/contracts/test/exchange/core.ts

@@ -1,6 +1,6 @@
 import { BlockchainLifecycle } from '@0xproject/dev-utils';
 import { assetProxyUtils, orderHashUtils } from '@0xproject/order-utils';
-import { AssetProxyId, RevertReasons, SignedOrder } from '@0xproject/types';
+import { AssetProxyId, RevertReason, SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as chai from 'chai';
@@ -147,7 +147,7 @@ describe('Exchange core', () => {
             signedOrder.signature = invalidSigHex;
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress),
-                RevertReasons.InvalidOrderSignature,
+                RevertReason.InvalidOrderSignature,
             );
         });
 
@@ -156,7 +156,7 @@ describe('Exchange core', () => {
             await exchangeWrapper.fillOrderAsync(signedOrder, takerAddress);
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress),
-                RevertReasons.OrderUnfillable,
+                RevertReason.OrderUnfillable,
             );
         });
     });
@@ -170,7 +170,7 @@ describe('Exchange core', () => {
         it('should throw if not sent by maker', async () => {
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrderAsync(signedOrder, takerAddress),
-                RevertReasons.InvalidMaker,
+                RevertReason.InvalidMaker,
             );
         });
 
@@ -181,7 +181,7 @@ describe('Exchange core', () => {
 
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrderAsync(signedOrder, makerAddress),
-                RevertReasons.OrderUnfillable,
+                RevertReason.OrderUnfillable,
             );
         });
 
@@ -192,7 +192,7 @@ describe('Exchange core', () => {
 
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrderAsync(signedOrder, makerAddress),
-                RevertReasons.OrderUnfillable,
+                RevertReason.OrderUnfillable,
             );
         });
 
@@ -202,7 +202,7 @@ describe('Exchange core', () => {
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress, {
                     takerAssetFillAmount: signedOrder.takerAssetAmount.div(2),
                 }),
-                RevertReasons.OrderUnfillable,
+                RevertReason.OrderUnfillable,
             );
         });
 
@@ -225,7 +225,7 @@ describe('Exchange core', () => {
             await exchangeWrapper.cancelOrderAsync(signedOrder, makerAddress);
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrderAsync(signedOrder, makerAddress),
-                RevertReasons.OrderUnfillable,
+                RevertReason.OrderUnfillable,
             );
         });
 
@@ -235,7 +235,7 @@ describe('Exchange core', () => {
             });
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrderAsync(signedOrder, makerAddress),
-                RevertReasons.OrderUnfillable,
+                RevertReason.OrderUnfillable,
             );
         });
 
@@ -255,7 +255,7 @@ describe('Exchange core', () => {
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress, {
                     takerAssetFillAmount: fillTakerAssetAmount2,
                 }),
-                RevertReasons.RoundingError,
+                RevertReason.RoundingError,
             );
         });
     });
@@ -267,7 +267,7 @@ describe('Exchange core', () => {
             const lesserOrderEpoch = new BigNumber(0);
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrdersUpToAsync(lesserOrderEpoch, makerAddress),
-                RevertReasons.InvalidNewOrderEpoch,
+                RevertReason.InvalidNewOrderEpoch,
             );
         });
 
@@ -276,7 +276,7 @@ describe('Exchange core', () => {
             await exchangeWrapper.cancelOrdersUpToAsync(orderEpoch, makerAddress);
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.cancelOrdersUpToAsync(orderEpoch, makerAddress),
-                RevertReasons.InvalidNewOrderEpoch,
+                RevertReason.InvalidNewOrderEpoch,
             );
         });
 
@@ -410,7 +410,7 @@ describe('Exchange core', () => {
             const takerAssetFillAmount = signedOrder.takerAssetAmount;
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress, { takerAssetFillAmount }),
-                RevertReasons.InvalidAmount,
+                RevertReason.TransferFailed,
             );
         });
 
@@ -433,7 +433,7 @@ describe('Exchange core', () => {
             const takerAssetFillAmount = signedOrder.takerAssetAmount;
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress, { takerAssetFillAmount }),
-                RevertReasons.InvalidAmount,
+                RevertReason.TransferFailed,
             );
         });
 
@@ -450,7 +450,7 @@ describe('Exchange core', () => {
             const takerAssetFillAmount = signedOrder.takerAssetAmount.div(2);
             return expectRevertReasonOrAlwaysFailingTransactionAsync(
                 exchangeWrapper.fillOrderAsync(signedOrder, takerAddress, { takerAssetFillAmount }),
-                RevertReasons.RoundingError,
+                RevertReason.RoundingError,
             );
         });
     });