Reinclude demo, as it is used by the test suite

Change-Id: I8a3ea357f18a1fa0a423f6698d3c8fbe921560cf
diff --git a/.dockerignore b/.dockerignore
index 23b6ac1..614d24f 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -17,5 +17,4 @@
 /dev/js/src/custom
 /lib/Kalamar/Plugin/Announcements.pm
 /script/hypnotoad.pid
-/dev/css
-/dev/demo
\ No newline at end of file
+/dev/css
\ No newline at end of file