Update sbt-scalajs, scalajs-compiler to 0.6.27 (#74)

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.2.1")
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "0.6.26")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "0.6.27")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "0.6.0")
 addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.2")
 addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "0.3.0")