Task: Add method to get all services by feature.

featuren/models/feature.py

@@ -1,5 +1,5 @@
 from apistar import types, validators
-from orator import Model
+from orator import Model, accessor
 from models.features_service import FeaturesServices
 
 import logging
@@ -33,7 +33,22 @@ class Feature(Model):
 
     __fillable__ = ["id", "version", "enabled", "deny"]
 
+    __appends__ = ["services"]
+
+    @accessor
+    def services(self):
+        """
+        Method to get all services by feature.
+        """
+        services = FeaturesServices.all().where("feature_id", self.id)
+        services.transform(lambda item: item.service_id)
+
+        return services.serialize()
+
     def update_services(self, services):
+        """
+        Method to update the list of available services for feature.
+        """
 
         try: