Drop usage of scala.xml.pull

Used in https://github.com/dnvriend/akka-persistence-jdbc/blob/master/src/test/scala/akka/persistence/jdbc/util/ClasspathResources.scala

See https://github.com/scala/scala-xml/issues/193.  They've been removed in upcoming scala-xml 2: https://github.com/scala/scala-xml/pull/293.