Move xos-db into it's own chart

Have it issue it's own PersistentVolumeClaim if required

Change-Id: I408559b2cf4481e011e47c310147fd36c8c284bc
diff --git a/xos-core/requirements.yaml b/xos-core/requirements.yaml
index 05b5a9e..62de4ca 100644
--- a/xos-core/requirements.yaml
+++ b/xos-core/requirements.yaml
@@ -14,6 +14,9 @@
 # limitations under the License.
 
 dependencies:
+- name: xos-db
+  version: 0.1.0-dev0
+  repository: file://../xos-db
 - name: xos-gui
   version: 1.0.1
   repository: file://../xos-gui