build,travis: don't try to test deleted packages

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

.travis_do.sh

@@ -58,7 +58,7 @@ download_sdk() {
 # test_package call make download check for very new/modified package
 test_packages2() {
 	# search for new or modified packages. PKGS will hold a list of package like 'admin/muninlite admin/monit ...'
-	PKGS=$(git diff --name-only "$TRAVIS_COMMIT_RANGE" | grep 'Makefile$' | grep -v '/files/' | awk -F'/Makefile' '{ print $1 }')
+	PKGS=$(git diff --diff-filter=d --name-only "$TRAVIS_COMMIT_RANGE" | grep 'Makefile$' | grep -v '/files/' | awk -F'/Makefile' '{ print $1 }')
 
 	if [ -z "$PKGS" ] ; then
 		echo_blue "No new or modified packages found!"