Update Service Architecture.md

Cheat Sheets/Solutions/Service Architecture.md

@@ -4,6 +4,11 @@
 - ROCA: [Resource-Oriented Client Architecture](http://roca-style.org/)
 - Mosaic: [Frontend Microservices](https://www.mosaic9.org/)
 
+## Feature Management
+
+- [Feature Flags](http://swreflections.blogspot.de/2014/08/feature-toggles-are-one-of-worst-kinds.html)
+- [Levels of Feature Management](https://thenewstack.io/level-feature-management-right-team/?utm_content=buffer1b569&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer)
+
 ## Documentation
 
 - Pivio: [Documenting Microservices](http://pivio.io/)
@@ -13,3 +18,4 @@
 - Apache Airflow
 - Oozie (Hadoop)
 - Azkaban
+