Update sbt to 1.3.8

scala-steward · scala-steward · commit 16daaae7b36a · 2020-02-04T00:03:16.000+01:00
diff --git a/project/build.properties b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.3.7
+sbt.version=1.3.8
