Split tokens package into erc20 and erc721

contracts/exchange/test/dispatcher.ts

@@ -1,4 +1,11 @@
-import { artifacts as proxyArtifacts, ERC20ProxyContract, ERC721ProxyContract } from '@0x/contracts-asset-proxy';
+import {
+    artifacts as proxyArtifacts,
+    ERC20ProxyContract,
+    ERC20Wrapper,
+    ERC721ProxyContract,
+    ERC721Wrapper,
+} from '@0x/contracts-asset-proxy';
+import { DummyERC20TokenContract } from '@0x/contracts-erc20';
 import {
     chaiSetup,
     constants,
@@ -8,7 +15,6 @@ import {
     txDefaults,
     web3Wrapper,
 } from '@0x/contracts-test-utils';
-import { DummyERC20TokenContract } from '@0x/contracts-tokens';
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils } from '@0x/order-utils';
 import { AssetProxyId, RevertReason } from '@0x/types';
@@ -18,13 +24,10 @@ import { LogWithDecodedArgs } from 'ethereum-types';
 import * as _ from 'lodash';
 
 import {
+    artifacts,
     TestAssetProxyDispatcherAssetProxyRegisteredEventArgs,
     TestAssetProxyDispatcherContract,
-} from '../generated-wrappers/test_asset_proxy_dispatcher';
-import { artifacts } from '../src/artifacts';
-
-import { ERC20Wrapper } from './utils/erc20_wrapper';
-import { ERC721Wrapper } from './utils/erc721_wrapper';
+} from '../src';
 
 chaiSetup.configure();
 const expect = chai.expect;