move the alerting settings above the scrape configs

ref #22

prometheus/conf/prometheus.yml

@@ -9,6 +9,12 @@ rule_files:
   - "swarm_node.rules.yml"
   - "swarm_task.rules.yml"
 
+alerting:
+  alertmanagers:
+  - static_configs:
+    - targets:
+      - alertmanager:9093
+
 scrape_configs:
   - job_name: 'prometheus'
     static_configs:
@@ -35,9 +41,4 @@ scrape_configs:
       type: 'A'
       port: 9100
 
-alerting:
-  alertmanagers:
-  - static_configs:
-    - targets:
-      - alertmanager:9093