Added go-waitgroup (#2815)

README.md

@@ -789,6 +789,7 @@ Please take a quick gander at the [contribution guidelines](https://github.com/a
 * [go-flow](https://github.com/kamildrazkiewicz/go-flow) - Control goroutines execution order.
 * [go-tools/multithreading](https://github.com/nikhilsaraf/go-tools) - Manage a pool of goroutines using this lightweight library with a simple API.
 * [go-trylock](https://github.com/subchen/go-trylock) - TryLock support on read-write lock for Golang.
+* [go-waitgroup](https://github.com/pieterclaerhout/go-waitgroup) - Like `sync.WaitGroup` with error handling and concurrency control.
 * [gohive](https://github.com/loveleshsharma/gohive) - A highly performant and easy to use Goroutine pool for Go.
 * [gollback](https://github.com/vardius/gollback) - asynchronous simple function utilities, for managing execution of closures and callbacks.
 * [GoSlaves](https://github.com/themester/GoSlaves) - Simple and Asynchronous Goroutine pool library.