sbt itext jfreechart dependency blow up

app.scala

package org.example

import scalax.chart.api._

object Main extends App {
  val data = for {
    i <- 1 to 5
    category = i.toString
    date = new org.jfree.data.time.Day(i, 2, 1998)
    value = i * 2
  } yield category -> Map(date -> value)

  val chart = XYAreaChart.stacked(data.toTimeTable)

  chart.saveAsPDF("/tmp/my-chart.pdf")
}

assembly.sbt

addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.13.0")

build.properties

sbt.version=0.13.8

build.sbt

name := "test"

organization := "org.example"

version := "0.1.0-SNAPSHOT"

scalaVersion := "2.11.6"

libraryDependencies ++= Seq (
  "com.lowagie"              %  "itext"         % "4.2.1",
  "com.github.wookietreiber" %% "scala-chart"   % "0.4.2"
)