Added test to SampleLibraryTag

public/biopet-core/src/test/scala/nl/lumc/sasc/biopet/core/SampleLibraryTagTest.scala

+package nl.lumc.sasc.biopet.core
+
+import nl.lumc.sasc.biopet.utils.config.{Config, Configurable}
+import org.scalatest.Matchers
+import org.scalatest.testng.TestNGSuite
+import org.testng.annotations.Test
+
+/**
+  * Created by pjvanthof on 17/11/15.
+  */
+class SampleLibraryTagTest extends TestNGSuite with Matchers {
+  @Test
+  def testDefault: Unit = {
+    val o = new SampleLibraryTag {
+      override def root: Configurable = null
+      override def globalConfig = new Config(Map())
+    }
+    o.sampleId shouldBe None
+    o.libId shouldBe None
+  }
+
+  @Test
+  def testInherit: Unit = {
+    val o1 = new SampleLibraryTag {
+      override def root: Configurable = null
+      override def globalConfig = new Config(Map())
+    }
+    o1.sampleId = Some("sampleName")
+    o1.libId = Some("libName")
+    o1.sampleId shouldBe Some("sampleName")
+    o1.libId shouldBe Some("libName")
+
+    val o2 = new SampleLibraryTag {
+      override def root: Configurable = o1
+      override def globalConfig = new Config(Map())
+    }
+    o2.sampleId shouldBe o1.sampleId
+    o2.libId shouldBe o1.libId
+
+  }
+}

public/biopet-utils/src/main/scala/nl/lumc/sasc/biopet/utils/config/Configurable.scala

@@ -20,7 +20,7 @@ import nl.lumc.sasc.biopet.utils.ConfigUtils.ImplicitConversions
 
 trait Configurable extends ImplicitConversions {
   /** Should be object of parant object */
-  val root: Configurable
+  def root: Configurable
   def globalConfig: Config = if (root != null) root.globalConfig else Config.global
 
   /** suffix to the path */