message: Add accelerateTransaction to v2
diff: @@ -1018,7 +1018,8 @@ Wallet.prototype.prebuildTransaction = function(params, callback) {
  const whitelistedParams = _.pick(params, [
  'recipients', 'numBlocks', 'feeRate', 'maxFeeRate', 'minConfirms', 'enforceMinConfirmsForChange',
  'targetWalletUnspents', 'message', 'minValue', 'maxValue', 'sequenceId', 'lastLedgerSequence',
  - 'ledgerSequenceDelta', 'gasPrice', 'noSplitChange', 'unspents', 'changeAddress', 'instant', 'memo', 'addressType'
  + 'ledgerSequenceDelta', 'gasPrice', 'noSplitChange', 'unspents', 'changeAddress', 'instant', 'memo', 'addressType',
  + 'cpfpTxIds', 'cpfpFeeRate', 'maxFee'
  ]);
  if (params.reqId) {
  @@ -1135,6 +1136,28 @@ Wallet.prototype.prebuildAndSignTransaction = function(params, callback) {
  }).call(this).asCallback(callback);
  };
  +Wallet.prototype.accelerateTransaction = function(params, callback) {
  + return co(function *() {
  + // TODO(BG-9349): change the last check to > 0 and the error message once platform allows multiple transactions to
  + // be bumped in the same CPFP transaction
  + if (_.isUndefined(params.cpfpTxIds) || !Array.isArray(params.cpfpTxIds) || params.cpfpTxIds.length !== 1) {
  + const error = new Error('expecting cpfpTxIds to be an array of length 1');
  + error.code = 'cpfptxids_not_array';
  + throw error;
  + }
  +
  + if (_.isUndefined(params.cpfpFeeRate) && _.isUndefined(params.maxFeeRate)) {
  + debug('neither cpfpFeeRate nor maxFeeRate set in accelerateTransaction');
  + }
  +
  + if (_.isUndefined(params.maxFee)) {
  + debug('maxFee not set in accelerateTransaction');
  + }
  +
  + return yield this.prebuildAndSignTransaction(params);
  + }).call(this).asCallback(callback);
  +};
  +
  /**
  * Submits a half-signed transaction to BitGo
  * @param params
  