automation: add Fedora image to containerize script

At the same time sort the list alphabetically.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Doug Goldstein <cardoe@cardoe.com>

automation/scripts/containerize

@@ -19,10 +19,11 @@ case "_${CONTAINER}" in
     _centos6) CONTAINER="${BASE}/centos:6" ;;
     _centos7) CONTAINER="${BASE}/centos:7" ;;
     _centos72) CONTAINER="${BASE}/centos:7.2" ;;
-    _trusty) CONTAINER="${BASE}/ubuntu:trusty" ;;
-    _xenial) CONTAINER="${BASE}/ubuntu:xenial" ;;
+    _fedora) CONTAINER="${BASE}/fedora:latest";;
     _jessie) CONTAINER="${BASE}/debian:jessie" ;;
     _stretch|_) CONTAINER="${BASE}/debian:stretch" ;;
+    _trusty) CONTAINER="${BASE}/ubuntu:trusty" ;;
+    _xenial) CONTAINER="${BASE}/ubuntu:xenial" ;;
 esac
 
 # Use this variable to control whehter root should be used