Remove obsolete release

Change-Id: I677aafc92d68a7cb28d28fe6e10c1447a34a8d6a
diff --git a/packaging.mk b/packaging.mk
index b17c05f..1c873a8 100644
--- a/packaging.mk
+++ b/packaging.mk
@@ -2,7 +2,7 @@
 PPA=ppa:named-data/ppa-dev
 
 # List of target distributions
-DISTROS=trusty xenial zesty artful
+DISTROS=trusty xenial artful
 
 DEBUILD=debuild -S