Deserializer - Fix deserializer when data is null

[shilps1583]

Fixes issue #203

[martinezguillaume]

Here is my jsonapi-serializer+3.6.9.patch to solve this

diff --git a/node_modules/jsonapi-serializer/lib/deserializer.js b/node_modules/jsonapi-serializer/lib/deserializer.js
index 1cb7c1a..d8fc6e4 100644
--- a/node_modules/jsonapi-serializer/lib/deserializer.js
+++ b/node_modules/jsonapi-serializer/lib/deserializer.js
@@ -31,8 +31,9 @@ module.exports = function (opts) {
           return result
         });
     }
-
-    if (Array.isArray(jsonapi.data)) {
+    if (!jsonapi.data) {
+      return jsonapi.data
+    } else if (Array.isArray(jsonapi.data)) {
       return collection();
     } else {
       return resource();