first shoot
Merge latest changes from branch 'master' into 40-AnonymousAccessLoadBalancer
make use of resource types
set correct response type for request summary servlet
Merge pull request #40 from joerghoh/40-AnonymousAccessLoadBalancer

so I moved all servlets to /apps/healthcheck/servlet/* and made use of resource types to attach the servlets. 

currently we have:

- /apps/healthcheck/servlet/loadbalancer => http://host:port/apps/healthcheck/servlet/loadbalancer
- /apps/healthcheck/servlet/requestinfo => htp://host:port/apps/healthcheck/servlet/requestinfo.json

anonymous access is defined for both nodes. thus you can send requests without being logged in. admins can go in and change the ACL settings to restrict access further if required.

one thing to note is that in the latest version (5.6.1) anonymous access without user credentials is not allowed anymore by default on author instances. 

this means on an author after installing the healthcheck app the following won't work on an author instance (publish works fine though):

curl http://localhost:4502/apps/healthcheck/servlet/loadbalancer

But this works on author:

curl -u anonymous: http://localhost:4502/apps/healthcheck/servlet/loadbalancer

You can change this by enabling "Allow anonymous access" via http://host:port/system/console/configMgr/org.apache.sling.engine.impl.auth.SlingAuthenticator. But I'd suggest to leave these settings as they are or security reasons and go with providing the anonymous user name (password is not required as you can see).