explicitly set health system to enhanced

Author: Michael Wunderlich

.ebextensions/dev.config

@@ -6,6 +6,8 @@ option_settings:
     IgnoreHealthCheck: "true"
   aws:elasticbeanstalk:monitoring:
     Automatically Terminate Unhealthy Instances: "false"
+  aws:elasticbeanstalk:healthreporting:system:
+    SystemType: enhanced
 commands:
   01-clear-logs:
     command: cd /var/log/ && rm nginx/* && mv *.gz rotated