update orderbook (avelino#2390)

README.md

@@ -611,6 +611,7 @@ Please take a quick gander at the [contribution guidelines](https://github.com/a
 * [go-finance](https://github.com/alpeb/go-finance) - Library of financial functions for time value of money (annuities), cash flow, interest rate conversions, bonds and depreciation calculations.
 * [go-money](https://github.com/rhymond/go-money) - Implementation of Fowler's Money pattern.
 * [ofxgo](https://github.com/aclindsa/ofxgo) - Query OFX servers and/or parse the responses (with example command-line client).
+* [orderbook](https://github.com/i25959341/orderbook) - Matching Engine for Limit Order Book in Golang.
 * [techan](https://github.com/sdcoffey/techan) - Technical analysis library with advanced market analysis and trading strategies.
 * [transaction](https://github.com/claygod/transaction) - Embedded transactional database of accounts, running in multithreaded mode.
 * [vat](https://github.com/dannyvankooten/vat) - VAT number validation & EU VAT rates.