Remove devstack-single-node-fedora-27

There is no projects using this and allows openstack-infra to delete
fedora-27 images.

Change-Id: I37d482dd2b5e099c370ab693ff430cb9c56360f8
Depends-On: https://review.openstack.org/588369
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

Author: pabelanger

.zuul.yaml

@@ -38,16 +38,6 @@
         nodes:
           - controller
 
-- nodeset:
-    name: devstack-single-node-fedora-27
-    nodes:
-      - name: controller
-        label: fedora-27
-    groups:
-      - name: tempest
-        nodes:
-          - controller
-
 - nodeset:
     name: devstack-single-node-fedora-latest
     nodes: