Add product property to the root Sushy object

Chages made to sushy/main.py
product property is the product associated with this Redfish service.

Change-Id: I2ab5bd73ac609a8563807bdc0d1c1825cd5b4bba

sushy/main.py

@@ -37,6 +37,9 @@ class Sushy(base.ResourceBase):
     uuid = base.Field('UUID')
     """The Redfish root service UUID"""
 
+    product = base.Field('Product')
+    """The product associated with this Redfish service"""
+
     _systems_path = base.Field(['Systems', '@odata.id'])
     """SystemCollection path"""
 

sushy/tests/unit/json_samples/root.json

@@ -4,6 +4,7 @@
     "Name": "Root Service",
     "RedfishVersion": "1.0.2",
     "UUID": "92384634-2938-2342-8820-489239905423",
+    "Product": "Product",
     "Systems": {
         "@odata.id": "/redfish/v1/Systems"
     },

sushy/tests/unit/test_main.py

@@ -54,6 +54,7 @@ class MainTestCase(base.TestCase):
         self.assertEqual('1.0.2', self.root.redfish_version)
         self.assertEqual('92384634-2938-2342-8820-489239905423',
                          self.root.uuid)
+        self.assertEqual('Product', self.root.product)
         self.assertEqual('/redfish/v1/Systems', self.root._systems_path)
         self.assertEqual('/redfish/v1/Managers', self.root._managers_path)
         self.assertEqual('/redfish/v1/SessionService',