Build tut-core for Scala 2.10 again

.travis.yml

@@ -12,6 +12,9 @@ before_cache:
 
 matrix:
   include:
+    - scala: 2.10.6
+      env: TEST_SCRIPTED=0
+      jdk: oraclejdk8
     - scala: 2.11.11
       env: TEST_SCRIPTED=1
       jdk: oraclejdk8

core/build.sbt

@@ -6,9 +6,16 @@ libraryDependencies ++= Seq(
 
 scalaVersion := "2.12.3"
 
-crossScalaVersions := Seq("2.11.11", "2.12.3", "2.13.0-M1")
+crossScalaVersions := Seq("2.10.6", "2.11.11", "2.12.3", "2.13.0-M1")
 
-libraryDependencies += "org.scala-lang.modules" %% "scala-xml" % "1.0.5"
+libraryDependencies := {
+  CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((2, scalaMajor)) if scalaMajor >= 11 =>
+      libraryDependencies.value :+ "org.scala-lang.modules" %% "scala-xml" % "1.0.6"
+    case _ =>
+      libraryDependencies.value
+  }
+}
 
 // scripted-plugin is enabled by default, in particular in this non-sbt subproject
 // this means that switching to 2.11.11 will result in non-existent dependencies