Updated tk-alias to v4.2.1

Release notes: https://github.com/shotgunsoftware/tk-alias/releases/tag/v4.2.1

Author: toolkitty

env/includes/common/engines.yml

@@ -42,7 +42,7 @@ common.engines.tk-flame.location:
 common.engines.tk-alias.location:
   type: app_store
   name: tk-alias
-  version: v4.2.0
+  version: v4.2.1
 common.engines.tk-vred.location:
   type: app_store
   name: tk-vred