Add basic nextcloud deployment

Uses php-fpm image and is served through a simple caddy server.
Automatically deploys by default and can be automatically deployed with
smtp e-mail sending and s3 primary object storage optionally if desired.

Utilizes some necessary hackery for container ordering and startup so
startup is relatively slow (takes around 2-5 minutes at least) but once
running should be stable and uninterrupted.

Implements health-checks for all involved containers.

Switch apache for php-fpm image

roles/nextcloud/files/Caddyfile

@@ -0,0 +1,32 @@
+:80 {
+	root * /var/www/html
+	file_server
+
+	php_fastcgi app:9000
+	header {
+		# enable HSTS
+		# Strict-Transport-Security max-age=31536000;
+	}
+
+	redir /.well-known/carddav /remote.php/dav 301
+	redir /.well-known/caldav /remote.php/dav 301
+
+	# .htaccess / data / config / ... shouldn't be accessible from outside
+	@forbidden {
+		path /.htaccess
+		path /data/*
+		path /config/*
+		path /db_structure
+		path /.xml
+		path /README
+		path /3rdparty/*
+		path /lib/*
+		path /templates/*
+		path /occ
+		path /console.php
+	}
+
+	respond @forbidden 404
+
+}
+