Playframework, Scala - not able to enable Specs2 test dependency

In my build.sbt file, I have added spec2 dependency - libraryDependencies += specs2 % Test. However, after sbt update, I'm not able to find org.specs2._ package. I'm currently in intellij ide, with sbt version 0.13.8, play version 2.4.6. I have tried cleaning .ivy2 cache, and intellij invalidateCache/restart as well.

build.sbt

name := "example"

version := "1.2.2"

organization := "com.abc"

scalaVersion := "2.11.8"

resolvers +=
  "Artifactory" at "http://ift.tt/2qiJaCq"

libraryDependencies ++= Seq(
  "com.xxx" %% "xxx" % "1.2.3" % "compile" withSources() changing(),
  specs2 % Test
)

lazy val `rew3-serviceaccount` = (project in file(".")).enablePlugins(PlayScala)

publishMavenStyle := true

isSnapshot := false

publishTo := //url

credentials += Credentials("Artifactory Realm", "xx.xx.xx.xx.", "xx", "xx")