Merge pull request #711 from typelevel/update/doctest-runtime-0.13.0

Update doctest-runtime, sbt-doctest to 0.13.0

Author: sh0hei

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.22.0")
-addSbtPlugin("io.github.sbt-doctest" % "sbt-doctest" % "0.12.5")
+addSbtPlugin("io.github.sbt-doctest" % "sbt-doctest" % "0.13.0")
 addSbtPlugin("org.typelevel" % "sbt-typelevel" % "0.8.6")
 addSbtPlugin("org.typelevel" % "sbt-typelevel-site" % "0.8.6")
 addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.5.12")