K8s manifest files updated to use docker tag 7 instead of latest

Change-Id: I5cbec8d6c4aed6612121391254f9f7e4d8fa0e6c
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/installers/docker/osm_pods/keystone.yaml b/installers/docker/osm_pods/keystone.yaml
index 8a976cf..7152059 100644
--- a/installers/docker/osm_pods/keystone.yaml
+++ b/installers/docker/osm_pods/keystone.yaml
@@ -45,7 +45,7 @@
     spec:
       containers:
       - name: keystone
-        image: opensourcemano/keystone:latest
+        image: opensourcemano/keystone:7
         ports:
         - containerPort: 5000
           protocol: TCP