Update cats-core, cats-free to 2.1.1 (#351)

Co-authored-by: Rafa Paradela <rafa.p@47deg.com>

Author: scala-steward

project/ProjectPlugin.scala

@@ -22,7 +22,7 @@ object ProjectPlugin extends AutoPlugin {
 
     lazy val V = new {
       val base64: String     = "0.2.9"
-      val cats: String       = "2.1.0"
+      val cats: String       = "2.1.1"
       val catsEffect: String = "2.0.0"
       val circe: String      = "0.13.0"
       val paradise: String   = "2.1.1"