Add additional Conflicts/Replaces on the 18.04 artwork package.

debian/changelog

@@ -1,3 +1,9 @@
+lubuntu-artwork (1.1) cosmic; urgency=medium
+
+  * Add additional Conflicts/Replaces on the 18.04 artwork package.
+
+ -- Simon Quigley <tsimonq2@ubuntu.com>  Wed, 16 May 2018 22:35:15 -0500
+
 lubuntu-artwork (1.0) cosmic; urgency=medium
 
   * Rename the Lubuntu Next Plymouth theme to Lubuntu, and retire the

debian/control

@@ -12,6 +12,8 @@ Vcs-Git: https://git.launchpad.net/lubuntu-artwork
 Package: lubuntu-artwork
 Architecture: all
 Depends: ${misc:Depends}
+Conflicts: lubuntu-artwork-18-04 (<< 1.0)
+Replaces: lubuntu-artwork-18-04 (<< 1.0)
 Description: artwork for Lubuntu
  Artwork for Lubuntu which contains the default wallpaper and default theming.