Perform read-only splits for the containers

The .gitsplit.yml file contains the configuration to be used by Jérémy
Derussé's docker-gitsplit container.

For usage instructions see https://github.com/jderusse/docker-gitsplit

.gitsplit.yml

@@ -0,0 +1,30 @@
+splits:
+  - prefix: "admin"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Admin.git"
+  - prefix: "clamav"
+    target: "https://${GH_TOKEN}@github.com/Mailu/ClamAV.git"
+  - prefix: "dovecot"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Dovecot.git"
+  - prefix: "fetchmail"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Fetchmail.git"
+  - prefix: "nginx-no-https"
+    target: "https://${GH_TOKEN}@github.com/Mailu/NGINX-no-HTTPS.git"
+  - prefix: "nginx"
+    target: "https://${GH_TOKEN}@github.com/Mailu/NGINX.git"
+  - prefix: "postfix"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Postfix.git"
+  - prefix: "radicale"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Radicale.git"
+  - prefix: "rainloop"
+    target: "https://${GH_TOKEN}@github.com/Mailu/RainLoop.git"
+  - prefix: "rmilter"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Rmilter.git"
+  - prefix: "roundcube"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Roundcube.git"
+  - prefix: "rspamd"
+    target: "https://${GH_TOKEN}@github.com/Mailu/Rspamd.git"
+
+origins:
+  - ^master$
+  - ^stable$
+  - ^\d+\.\d+$