message: chore(core): remove coroutines from src/bitgo
  Ticket:
diff: @@ -18,8 +18,6 @@ import bs58 = require('bs58');
  import * as common from './common';
  import { EnvironmentName, AliasEnvironments } from './v2/environments';
  import { NodeCallback, RequestTracer as IRequestTracer, V1Network } from './v2/types';
  -import * as Bluebird from 'bluebird';
  -import co = Bluebird.coroutine;
  import pjson = require('../package.json');
  import moment = require('moment');
  import * as _ from 'lodash';
  @@ -618,14 +616,10 @@ export class BitGo {
  /**
  * Create a basecoin object for a virtual token
  * @param tokenName
  - * @param callback
  */
  - token(tokenName: string, callback?: NodeCallback<BaseCoin>): Bluebird<BaseCoin> {
  - const self = this;
  - return co<BaseCoin>(function *() {
  - yield self.fetchConstants();
  - return self.coin(tokenName);
  - }).call(this).asCallback(callback);
  + async token(tokenName: string): Promise<BaseCoin> {
  + await this.fetchConstants();
  + return this.coin(tokenName);
  }
  /**
  