Use make-promises-safe as a preloader instead of manually importing

packages/order-watcher/test/event_watcher_test.ts

@@ -3,7 +3,6 @@ import { DoneCallback, LogEntry, LogEntryEvent } from '@0xproject/types';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as chai from 'chai';
 import * as _ from 'lodash';
-import 'make-promises-safe';
 import 'mocha';
 import * as Sinon from 'sinon';
 

packages/order-watcher/test/expiration_watcher_test.ts

@@ -6,7 +6,6 @@ import { DoneCallback, Token } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as chai from 'chai';
 import * as _ from 'lodash';
-import 'make-promises-safe';
 import 'mocha';
 import * as Sinon from 'sinon';
 

packages/order-watcher/test/global_hooks.ts

@@ -1,6 +1,5 @@
 import { devConstants } from '@0xproject/dev-utils';
 import { runV1MigrationsAsync } from '@0xproject/migrations';
-import 'make-promises-safe';
 
 import { provider } from './utils/web3_wrapper';
 

packages/order-watcher/test/order_watcher_test.ts

@@ -16,7 +16,6 @@ import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as chai from 'chai';
 import * as _ from 'lodash';
-import 'make-promises-safe';
 import 'mocha';
 
 import { OrderWatcher } from '../src/order_watcher/order_watcher';