bump version to 3.1b1
diff --git a/Lib/idlelib/idlever.py b/Lib/idlelib/idlever.py
index 6191313..7ed0628 100644
--- a/Lib/idlelib/idlever.py
+++ b/Lib/idlelib/idlever.py
@@ -1 +1 @@
-IDLE_VERSION = "3.1a2"
+IDLE_VERSION = "3.1b1"