[GR-16675] Set versions for next dev cycle.

Author: ansalond

mx.graalpython/suite.py

@@ -9,7 +9,7 @@
     "name": "graalpython",
     "versionConflictResolution": "latest",
 
-    "version": "20.0.0-beta.02",
+    "version": "19.1.0",
     "release": False,
     "groupId": "org.graalvm.graalpython",
     "url": "http://www.graalvm.org/",