Don't require adding type test-jar to classpathTypes

E.g. when adding dependencies with a tests classifier

sbt-coursier/src/main/scala/coursier/CoursierPlugin.scala

@@ -158,7 +158,10 @@ object CoursierPlugin extends AutoPlugin {
           Some(Configuration("docs", "", isPublic = true, extendsConfigs = Vector.empty, transitive = false))
 
       confs ++ extraSources.toSeq ++ extraDocs.toSeq
-    }
+    },
+    // Tests artifacts from Maven repositories are given this type.
+    // Adding it here so that these work straightaway.
+    classpathTypes += "test-jar"
   )
 
   override lazy val buildSettings = super.buildSettings ++ Seq(

sbt-coursier/src/sbt-test/sbt-coursier/classifiers/build.sbt

@@ -0,0 +1,2 @@
+scalaVersion := "2.11.8"
+libraryDependencies += "org.jclouds.api" % "nova" % "1.5.9" classifier "tests"

sbt-coursier/src/sbt-test/sbt-coursier/classifiers/project/plugins.sbt

@@ -0,0 +1,11 @@
+{
+  val pluginVersion = sys.props.getOrElse(
+    "plugin.version",
+    throw new RuntimeException(
+      """|The system property 'plugin.version' is not defined.
+         |Specify this property using the scriptedLaunchOpts -D.""".stripMargin
+    )
+  )
+
+  addSbtPlugin("io.get-coursier" % "sbt-coursier" % pluginVersion)
+}

sbt-coursier/src/sbt-test/sbt-coursier/classifiers/src/main/scala/Main.scala

@@ -0,0 +1,17 @@
+import java.io.File
+import java.nio.file.Files
+
+import scala.util.Try
+
+object Main extends App {
+
+  def classFound(clsName: String) = Try(
+    Thread.currentThread()
+      .getContextClassLoader()
+      .loadClass(clsName)
+  ).toOption.nonEmpty
+
+  val classifierTest = classFound("org.jclouds.openstack.nova.functions.ParseServerFromJsonResponseTest")
+
+  assert(classifierTest, s"Couldn't find classifierTest")
+}

sbt-coursier/src/sbt-test/sbt-coursier/classifiers/test

@@ -0,0 +1 @@
+> run