add routes for all apps

all apps get a route assigned when using v3-zdt-push.

> By default, the web process has a route and one instance. Other processes have zero instances by default.

([source](https://docs.cloudfoundry.org/devguide/multiple-processes.html))

When we push apps to multiple environments they need different routes
or the second push will fail, so this means that we need to define
routes ourselves for every app.

We're also manually flagging the health-check as either "http" or
"process" - http for the api, process for all others.

If not specified, healthcheck is set to `port` by cloudfoundry - we've
seen some issues with upgrading the deployment from v2 to v3 when using
port - it adds apps to load balancer when they're not ready, which can
result in 404s. by setting healthcheck to http it'll wait for the
/status endpoint to return 200, which will wait for flask to get
everything up and running properly

manifest.yml.j2

@@ -1,9 +1,10 @@
 {%- set app_vars = {
   'notify-api': {'NOTIFY_APP_NAME': 'api', 'disk_quota': '2G', 'sqlalchemy_pool_size': 20, 'routes': {
-      'preview': ['notify-api-preview.cloudapps.digital', 'api.notify.works'],
-      'staging': ['notify-api-staging.cloudapps.digital', 'api.staging-notify.works'],
-      'production': ['notify-api-production.cloudapps.digital', 'api.notifications.service.gov.uk'],
-    }
+      'preview': ['api.notify.works'],
+      'staging': ['api.staging-notify.works'],
+      'production': ['api.notifications.service.gov.uk'],
+    },
+    'healthcheck-endpoint': '/_status?simple=true',
   },
   'notify-api-db-migration': {'NOTIFY_APP_NAME': 'api', 'instances': 0},
 
@@ -33,24 +34,24 @@ applications:
     memory: {{ app.get('memory', '1G') }}
     disk_quota: {{ app.get('disk_quota', '1G')}}
 
-    {% if 'routes' in app -%}
     routes:
-      {%- for route in app['routes'][environment] %}
+      {%- for route in app.get('routes', {}).get(environment, []) %}
       - route: {{ route }}
-      {%- endfor -%}
-    {%- elif environment in app.get('local_statsd', []) -%}
-    health-check-type: none
-    routes:
+      {%- endfor%}
       - route: {{ CF_APP }}-{{ environment }}.cloudapps.digital
-    {%- else -%}
-    health-check-type: none
-    no-route: true
+    {% if 'healthcheck-endpoint' in app %}
+    health-check-type: http
+    health-check-http-endpoint: {{ app['healthcheck-endpoint'] }}
+    {% else %}
+    health-check-type: process
     {% endif %}
 
     services:
       - notify-db
       - logit-ssl-syslog-drain
-      {% if environment in app.get('local_statsd', []) %}- notify-prometheus{% endif %}
+      {% if environment in app.get('local_statsd', []) -%}
+      - notify-prometheus
+      {% endif %}
 
     env:
       NOTIFY_APP_NAME: {{ app.get('NOTIFY_APP_NAME', CF_APP.replace('notify-', '')) }}