Generate compiler warnings for unused code

backend-services/feed-service/build.sbt

@@ -6,6 +6,8 @@ version := "1.0.0"
 lazy val root = (project in file(".")).enablePlugins(PlayScala)
 
 scalaVersion := "2.13.10"
+scalacOptions ++= Seq("-Ywarn-unused")
+
 
 libraryDependencies += guice
 libraryDependencies += "org.scalatestplus.play" %% "scalatestplus-play" % "5.0.0" % Test