Set newer scalajs version pulled from ammonite explicitly

* Update things scalajs depends on a newer version
* Update Scala versions

build.sbt

@@ -1,6 +1,9 @@
+// shadow sbt-scalajs' crossProject and CrossType from Scala.js 0.6.x
+import sbtcrossproject.CrossPlugin.autoImport.{crossProject, CrossType}
+
 val commonSettings = Seq(
- scalaVersion := "2.11.11",
- crossScalaVersions := Seq("2.11.11", "2.12.2"),
+ scalaVersion := "2.11.12",
+ crossScalaVersions := Seq("2.11.12", "2.12.7"),
  scalacOptions ++= Seq(
  "-feature", "-deprecation",
  "-Xlint", "-Xfatal-warnings"
@@ -40,7 +43,8 @@ lazy val publishing = Seq(
  publishTo := Some(Opts.resolver.sonatypeStaging)
 )
 
-val core = crossProject.in(file("core"))
+val core = crossProject(JSPlatform, JVMPlatform)
+ .in(file("core"))
  .settings(commonSettings)
  .settings(
  name := "reftree",
@@ -76,7 +80,8 @@ val core = crossProject.in(file("core"))
 lazy val coreJVM = core.jvm
 lazy val coreJS = core.js
 
-val demo = crossProject.in(file("demo"))
+val demo = crossProject(JSPlatform, JVMPlatform)
+ .in(file("demo"))
  .settings(commonSettings)
  .dependsOn(core)
  .settings(

demo/js/src/main/scala/reftree/demo/JsDemo.scala

@@ -3,11 +3,10 @@ package reftree.demo
 import reftree.diagram.Animation
 import reftree.render.Renderer
 
-import scala.scalajs.js
 import org.scalajs.dom
 
-object JsDemo extends js.JSApp {
- def main(): Unit = {
+object JsDemo {
+ def main(args: Array[String]): Unit = {
  val renderer = Renderer()
  import renderer._
 

project/build.properties

@@ -1 +1,2 @@
-sbt.version=0.13.13
+sbt.version=0.13.17
+

project/plugins.sbt

@@ -4,7 +4,7 @@ addSbtPlugin("org.tpolecat" % "tut-plugin" % "0.5.2")
 
 addSbtPlugin("io.get-coursier" % "sbt-coursier" % "1.0.0-M15-1")
 
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "0.6.17")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "0.6.25")
 
 addSbtPlugin("com.typesafe.sbt" % "sbt-site" % "1.2.1")
 
@@ -15,3 +15,5 @@ addSbtPlugin("com.dwijnand" % "sbt-dynver" % "1.3.0")
 addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "1.1")
 
 addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.0")
+
+addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "0.6.0")