Add datastore tests for setting leafrefs

Change-Id: I1a9eecac7cd91cc5422de2400779306d313a7ad2
diff --git a/example-schema.yang b/example-schema.yang
index 2248c28..498446e 100644
--- a/example-schema.yang
+++ b/example-schema.yang
@@ -63,6 +63,12 @@
         }
     }
 
+    leaf bossPerson {
+        type leafref {
+            path '../aha:person/name';
+        }
+    }
+
     grouping upAndDown {
         leaf up {
             type boolean;