Finished postgres role

README.md

@@ -9,6 +9,7 @@ Technical dependencies on host machine (Python 3.5+):
 * python3
 * python3-pip
 * python3-apt
+* python3-selinux
 
 Technical dependencies on managed machines:
 
@@ -27,3 +28,4 @@ update the variable values.
 All playbooks expect a fresh Uberspace with SSH key set up via
 management dashboard.
 
+* postgres setup: ``ansible-playbook -i hosts postgres.yml``