Golden Rules

1. Add '' or "" to interpolated values in a logger message. It will help to avoid confusing with spaces (" ")
  // incorrect:
  Logger.info("Received treatment: $treatment")
  // correct:
  Logger.info("Received treatment: '$treatment'")
2. in build.sbt use '%%' pattern instead of '%'. It will help with upgrading in the future
  // incorrect:
  "com.typesafe.play" % "play-slick_2.11" % "3.0.1"
  // correct:
  "com.typesafe.play" %% "play-slick" % "3.0.1"
3. Use Seq instead of List in case classes to avoid problems with Json (de)-serializing:
  // incorrect
  case class Images(userId: Long, images: List[String])
  implicit val jsonFormat = Json.format[Images]
  // correct
  case class Images(userId: Long, images: Seq[String])
  implicit val jsonFormat = Json.format[Images]