Merge pull request #372 from plantuml-stdlib/start-v2.12.0-beta1

Update version with first beta of v2.12.0 (v2.11.0 was created based on previous commit)

Author: kirchsth

C4.puml

@@ -13,7 +13,7 @@
 ' ##################################
 !function C4Version()
   ' 2 spaces and ' are used as unique marker, that the release scripts makes the correct version update
-  !$c4Version  =  "2.11.0beta1"
+  !$c4Version  =  "2.12.0beta1"
   !return $c4Version
 !end function