Add contracts to packages, fix most linting errors

packages/contracts/util/order_factory.ts

@@ -0,0 +1,24 @@
+import {ZeroEx} from '0x.js';
+import {BigNumber} from 'bignumber.js';
+import * as _ from 'lodash';
+
+import {Order} from './order';
+import {DefaultOrderParams, OptionalOrderParams, OrderParams} from './types';
+
+export class OrderFactory {
+  private defaultOrderParams: DefaultOrderParams;
+  constructor(defaultOrderParams: DefaultOrderParams) {
+    this.defaultOrderParams = defaultOrderParams;
+  }
+  public async newSignedOrderAsync(customOrderParams: OptionalOrderParams = {}) {
+    const randomExpiration = new BigNumber(Math.floor((Date.now() + (Math.random() * 100000000000)) / 1000));
+    const orderParams: OrderParams = _.assign({}, {
+      expirationTimestampInSec: randomExpiration,
+      salt: ZeroEx.generatePseudoRandomSalt(),
+      taker: ZeroEx.NULL_ADDRESS,
+    }, this.defaultOrderParams, customOrderParams);
+    const order = new Order(orderParams);
+    await order.signAsync();
+    return order;
+  }
+}