Update sbt to 1.3.12 (#504)

scala-steward · web-flow · commit 2e0b8ae8f85b · 2020-06-04T14:42:32.000+02:00
diff --git a/project/build.properties b/project/build.properties
@@ -1 +1 @@
-sbt.version = 1.3.10
+sbt.version = 1.3.12
