build.sbt

lazy val akkaHttpVersion = "10.0.11"
lazy val akkaVersion    = "2.5.11"
val circeVersion = "0.9.3"

lazy val root = (project in file(".")).
  settings(
    inThisBuild(List(
      organization    := "com.example",
      scalaVersion    := "2.12.4"
    )),
    name := "akka-http-websockets",
    libraryDependencies ++= Seq(
      "com.typesafe.akka" %% "akka-http"            % akkaHttpVersion,
      "com.typesafe.akka" %% "akka-stream"          % akkaVersion,

      "com.typesafe.akka" %% "akka-http-testkit"    % akkaHttpVersion % Test,
      "com.typesafe.akka" %% "akka-testkit"         % akkaVersion     % Test,
      "com.typesafe.akka" %% "akka-stream-testkit"  % akkaVersion     % Test,
      "org.scalatest"     %% "scalatest"            % "3.0.1"         % Test
    )
    ++ Seq(
      "io.circe" %% "circe-core",
      "io.circe" %% "circe-generic",
      "io.circe" %% "circe-generic-extras",
      "io.circe" %% "circe-parser"
    ).map(_ % circeVersion)
  )