title: How to find out which Play version I'm using?
body: <p>Kinda silly question, but I used <a href="https://typesafe.com/activator">Activator</a> to get started with the play framework, and now need to see what version I'm using. 2.3 came out with support for docker, but when I put </p>
  
  <p><code>dockerExposedPorts in Docker := Seq(9000, 9443)</code></p>
  
  <p>in my <code>build.sbt</code>, it complains it doesn't know what dockerExposedPorts is, so I'm thinking I might be running 2.2. </p>