Replace lodash with built-ins where possible to reduce bundle size (#1766)

* add tslint rule to disallow lodash.isUndefined

* add tslint rule to disallow lodash.isNull

* apply fixes

contracts/extensions/test/utils/balance_threshold_wrapper.ts

@@ -12,7 +12,6 @@ import { SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import { TransactionReceiptWithDecodedLogs } from 'ethereum-types';
-import * as _ from 'lodash';
 
 import { artifacts, BalanceThresholdFilterContract } from '../../src';
 
@@ -264,7 +263,7 @@ export class BalanceThresholdWrapper {
         gas?: number,
     ): Promise<TransactionReceiptWithDecodedLogs> {
         const signedExchangeTx = this._signerTransactionFactory.newSignedTransaction(abiEncodedExchangeTxData);
-        const txOpts = _.isUndefined(gas) ? { from } : { from, gas };
+        const txOpts = gas === undefined ? { from } : { from, gas };
         const txHash = await this._balanceThresholdFilter.executeTransaction.sendTransactionAsync(
             signedExchangeTx.salt,
             signedExchangeTx.signerAddress,