Get rid of deprecation warnings.

lib/featureApi.js

@@ -16,7 +16,7 @@ module.exports = function (app) {
             if (feature) {
                 res.json(feature);
             } else {
-                res.json(404, {error: 'Could not find feature'});
+                res.status(404).json({error: 'Could not find feature'});
             }
         });
     });
@@ -28,7 +28,7 @@ module.exports = function (app) {
         var errors = req.validationErrors();
 
         if (errors) {
-            res.json(400, errors);
+            res.status(400).json(errors);
             return;
         }