Update scala-library to 2.12.13 (#175)

Author: scala-steward

build.sbt

@@ -12,7 +12,7 @@ lazy val V = new {
   val evilplot = "0.7.0"
   val kindProjector = "0.10.3"
   val rainier = "0.2.3"
-  val scala = "2.12.10"
+  val scala = "2.12.13"
   val scalacheck = "1.15.3"
   val scalatest = "3.1.0"
   val scalaTestPlus = "3.1.0.1"