message: refactor(core): use bip32 in xtz
  Issue:
diff: /**
  * @prettier
  */
  +import * as bip32 from 'bip32';
  import * as Bluebird from 'bluebird';
  import { CoinFamily, BaseCoin as StaticsBaseCoin } from '@bitgo/statics';
  const co = Bluebird.coroutine;
  @@ -25,7 +26,6 @@ import { BitGo } from '../../bitgo';
  import { NodeCallback } from '../types';
  import BigNumber from 'bignumber.js';
  import { MethodNotImplementedError } from '../../errors';
  -import * as bitcoin from '@bitgo/utxo-lib';
  export interface XtzSignTransactionOptions extends SignTransactionOptions {
  txPrebuild: TransactionPrebuild;
  @@ -168,7 +168,7 @@ export class Xtz extends BaseCoin {
  * @returns {string} derived private key
  */
  deriveKeyWithPath({ key, path }: { key: string; path: string }): string {
  - const keychain = bitcoin.HDNode.fromBase58(key);
  + const keychain = bip32.fromBase58(key);
  const derivedKeyNode = keychain.derivePath(path);
  return derivedKeyNode.toBase58();
  }
  