Save initialPackages in DB instead of memory

lib/db/api.js

@@ -176,6 +176,12 @@ dbapi.setDeviceOwner = function(serial, owner) {
   }))
 }
 
+dbapi.saveDeviceInitialPackages = function(serial, packages) {
+  return db.run(r.table('devices').get(serial).update({
+    initialPackages: packages
+  }))
+}
+
 dbapi.unsetDeviceOwner = function(serial) {
   return db.run(r.table('devices').get(serial).update({
     owner: null