Reactive Stream (1)

本周开始复习部分 Scala 的知识，并开始学习 Akka Stream 的基础部分。Akka Stream 是 Reactive Stream + [Sources, Sinks and FlowGraphs](http://typesafe.com/blog/sources-sinks-and-flowgraphs) + [Akka Stream experimental API](http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-M1) + [Reactive Stream presentation by Joshua Suereth](https://docs.google.com/presentation/d/16eITQAn4HIdD6rV_0upX8LVgDeKL4z4WGnxPPGuzj8o/edit#slide=id.p) + [Async database access with PostgreSQL, Play, Scala and Heroku](http://mauricio.github.io/2013/04/29/async-database-access-with-postgresql-play-scala-and-heroku.html) + [Reactive Stream & Akka HTTP](http://spray.io/msug/#/)