kube: add .volume field on PVCs and ConfigMaps

Change-Id: I93eec44bd6df4ecb0044a4797faa9bf6fd26802d
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1811
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/kube/postgres.libsonnet b/kube/postgres.libsonnet
index d5ffad4..40f43dc 100644
--- a/kube/postgres.libsonnet
+++ b/kube/postgres.libsonnet
@@ -78,7 +78,7 @@
             template+: {
                 spec+: {
                     volumes_: {
-                        data: kube.PersistentVolumeClaimVolume(postgres.volumeClaim),
+                        data: postgres.volumeClaim.volume,
                     },
                     containers_: {
                         postgres: kube.Container(postgres.makeName("postgres")) {