Import friwall role from network ansible scripts

To reuse alpine and nginx roles. Probably going to merge repos at some point.

roles/opensmtpd/tasks/main.yml

@@ -0,0 +1,9 @@
+- name: Install mail server
+  package:
+    name: opensmtpd
+
+- name: Enable mail server
+  service:
+    name: smtpd
+    enabled: yes
+    state: started