Start building rousette

Also, given that the CI-built images were already peaking at 395 MB used
in rootfs, add some breathing space.

Change-Id: Ia1b3485364ba0f3fa23b77c867ff51a9d8cefacc
diff --git a/.zuul.yaml b/.zuul.yaml
index 71a4ff2..51df62a 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -14,6 +14,7 @@
       - CzechLight/netconf-cli
       - CzechLight/velia
       - CzechLight/lldp-systemd-networkd-sysrepo
+      - CzechLight/rousette
       - github/CESNET/libyang
       - github/sysrepo/sysrepo
       - github/CESNET/libnetconf2