Update list of maintainers

Remove myself

announcement.msg

diff --git a/announcement.msg b/announcement.msg
index 1c0bcdd..1e32b3c 100644
--- a/announcement.msg
+++ b/announcement.msg
@@ -79,7 +79,6 @@
 
 The following people are currently responsible for maintaining PyYAML:
 
-* Tina Mueller
 * Ingy döt Net
 * Matt Davis