Bump version to 0.80-SNAPSHOT

Change-Id: I0d54461c67013de229e5f75b3531bdaf855144f0
diff --git a/Changes b/Changes
index ed17895..f6b5f0e 100644
--- a/Changes
+++ b/Changes
@@ -1,3 +1,5 @@
+# version 0.80-SNAPSHOT
+
 # version 0.79
 
 - Implement timeout rewrite