add "Exploring CQRS and Event Sourcing" (#2694)

free-programming-books.md

@@ -670,6 +670,7 @@
 * [Domain Driven Design Quickly](http://www.infoq.com/minibooks/domain-driven-design-quickly)
 * [DSL Engineering: Designing, Implementing and Using Domain-Specific Languages](http://dslbook.org) - Markus Voelter
 * [Evolving Architectures of FinTech](http://www.oreilly.com/programming/free/evolving-architectures-of-fintech.csp) *(Just fill the fields with any values)*
+* [Exploring CQRS and Event Sourcing](https://msdn.microsoft.com/en-us/library/jj554200.aspx) - (EPUB, PDF)
 * [Guide to the Software Engineering Body of Knowledge](http://www.computer.org/portal/web/swebok)
 * [How to Design Programs](http://www.htdp.org)
 * [How to Write Unmaintainable Code](http://mindprod.com/jgloss/unmain.html)