Add wallabag docker deployment role

Added role of wallabag. Can take a subdomain alias to be presented on a
different uri than its stack name.

All services contain a healthcheck for docker swarm to be informed of
their status.

Copy whoami template to wallabag role

Change non-domain domain name to localhost

Fix correct handler notify naming

Allow setting different subdomain alias than name

Add meta information

roles/wallabag/templates/upstream.json.j2

@@ -0,0 +1,38 @@
+{
+    "@id": "{{ stack.name }}_upstream",
+{% if server_domain is not undefined and not none %}   
+    "match": [
+        {
+            "host": [
+{% if subdomain_alias is not undefined and not none %}
+                "{{ subdomain_alias }}.{{ server_domain }}"
+{% else %}
+                "{{ stack.name }}.{{ server_domain }}"
+{% endif %}
+            ]
+        }
+    ],
+{% else %}
+    "match": [
+        {
+            "path": [
+{% if subdomain_alias is not undefined and not none %}
+                "/{{ subdomain_alias }}*"
+{% else %}
+                "/{{ stack.name }}*"
+{% endif %}
+            ]
+        }
+    ],
+{% endif %}
+    "handle": [
+        {
+            "handler": "reverse_proxy",
+            "upstreams": [
+                {
+                    "dial": "{{ stack.name }}_app:80"
+                }
+            ]
+        }
+    ]
+}