Update maintainers (#155)

Author: mathieu-benoit

MAINTAINERS.md

@@ -2,7 +2,7 @@
 
 The following is the list of maintainers for all Score repositories, in alphabetical order:
 
-- Ben Meier (Humanitec) [@astromechza](https://github.com/astromechza)
-- Chris Stephenson (Humanitec) [@chrishumanitec](https://github.com/chrishumanitec)
-- Mathieu Benoit (Humanitec) [@mathieu-benoit](https://github.com/mathieu-benoit)
+- Ben Meier (Oracle) [@astromechza](https://github.com/astromechza)
+- Chris Stephenson (Independent) [@chris-stephenson](https://github.com/chris-stephenson)
+- Mathieu Benoit (Docker) [@mathieu-benoit](https://github.com/mathieu-benoit)
 - Susa Tünker (Checkly) [@sujaya-sys](https://github.com/sujaya-sys)