title: SBT not producing jar file
body: <p>I am using SBT to manage the dependencies. The code compiles as shown below, but no jar file is generated. </p>
  
  <p>Interesting part is that earlier today, SBT was generating a jar file in the /target/spark-2.1/ directory. Now its only updating the classes. I cannot figure out what I am doing wrong.</p>
  
  <pre><code>$ sbt compile
  [info] Set current project to Spark for Beginners (in build file:/tmp/Scala3/)
  [info] Compiling 1 Scala source to /tmp/Scala3/target/scala-2.11/classes...
  [success] Total time: 10 s, completed Mar 1, 2017 5:25:29 PM
  </code></pre>
  
  <p>Please help me.</p>