Update sbt-scalajs, scalajs-compiler, ... to 1.3.1 (#314)

Author: scala-steward

.travis.yml

@@ -12,13 +12,13 @@ scala:
 
 env:
   - ADOPTOPENJDK=8     SCALAJS_VERSION=
-  - ADOPTOPENJDK=8     SCALAJS_VERSION=1.3.0
+  - ADOPTOPENJDK=8     SCALAJS_VERSION=1.3.1
   - ADOPTOPENJDK=11    SCALAJS_VERSION=
 
 matrix:
   exclude:
     - scala: 3.0.0-M1
-      env: ADOPTOPENJDK=8     SCALAJS_VERSION=1.3.0
+      env: ADOPTOPENJDK=8     SCALAJS_VERSION=1.3.1
   include:
     - scala: 2.11.12
       env: ADOPTOPENJDK=8     SCALANATIVE_VERSION=0.3.9

project/plugins.sbt

@@ -1,5 +1,5 @@
 val scalaJSVersion =
-  Option(System.getenv("SCALAJS_VERSION")).filter(_.nonEmpty).getOrElse("1.3.0")
+  Option(System.getenv("SCALAJS_VERSION")).filter(_.nonEmpty).getOrElse("1.3.1")
 
 val scalaNativeVersion =
   Option(System.getenv("SCALANATIVE_VERSION")).filter(_.nonEmpty).getOrElse("0.3.9")