Update sbt-softwaremill to 2.0.20 (#329)

Author: kciesielski

project/plugins.sbt

@@ -3,7 +3,7 @@ addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.15.0")
 addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.4.17")
 addSbtPlugin("com.eed3si9n" % "sbt-projectmatrix" % "0.9.2")
 
-val sbtSoftwareMillVersion = "2.0.19"
+val sbtSoftwareMillVersion = "2.0.20"
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-common" % sbtSoftwareMillVersion)
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-publish" % sbtSoftwareMillVersion)
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-browser-test-js" % sbtSoftwareMillVersion)