message: refactor(core): use bip32 in erc20Token
  Issue:
diff: /**
  * @prettier
  */
  -import { HDNode } from '@bitgo/utxo-lib';
  +import * as bip32 from 'bip32';
  import * as Bluebird from 'bluebird';
  import * as _ from 'lodash';
  import { BitGo } from '../../bitgo';
  @@ -153,8 +153,8 @@ export class Erc20Token extends Eth {
  let backupSigningKey;
  if (isKrsRecovery || isUnsignedSweep) {
  - const backupHDNode = HDNode.fromBase58(backupKey);
  - backupSigningKey = backupHDNode.getKey().getPublicKeyBuffer();
  + const backupHDNode = bip32.fromBase58(backupKey);
  + backupSigningKey = backupHDNode.publicKey;
  backupKeyAddress = `0x${optionalDeps.ethUtil.publicToAddress(backupSigningKey, true).toString('hex')}`;
  } else {
  let backupPrv;
  @@ -168,8 +168,8 @@ export class Erc20Token extends Eth {
  throw new Error(`Error decrypting backup keychain: ${e.message}`);
  }
  - const backupHDNode = HDNode.fromBase58(backupPrv);
  - backupSigningKey = backupHDNode.getKey().getPrivateKeyBuffer();
  + const backupHDNode = bip32.fromBase58(backupPrv);
  + backupSigningKey = backupHDNode.privateKey;
  backupKeyAddress = `0x${optionalDeps.ethUtil.privateToAddress(backupSigningKey).toString('hex')}`;
  }
  