[STORM-2564] We should provide a template for storm-cluster-auth.yaml

[liu-zhaokun]

https://issues.apache.org/jira/browse/STORM-2564
As the configuration which named storm.zookeeper.auth.payload should be filled in "storm-cluster-auth.yaml",and there isn't such a file.So, I think we should provide a template for storm-cluster-auth.yaml.

[liu-zhaokun]

@vesense
Could you help me review this PR?

[liu-zhaokun]

@HeartSaVioR
Hello,are you available to help me review this PR?

[HeartSaVioR]

If this is needed, why not adding storm.yaml.example and commenting it out? I don't think users want to copy a line from template file and paste to their storm.yaml.

[liu-zhaokun]

@HeartSaVioR
It says "Note that if this is set to something with a secret (as when using digest authentication) then it should only be set in the storm-cluster-auth.yaml file." in Config.java,line 1082. So I think we should provide
a template.

[liu-zhaokun]

@HeartSaVioR
Users needn't copy the configuration,storm.zookeeper.auth.payload, from storm-cluster-auth.yaml.template and paste to their storm.yaml.They only should add this configuration to storm-cluster-auth.yaml if they need.

[HeartSaVioR]

@liu-zhaokun Thanks for correcting. You're right. I'm not aware of that. +1

[liu-zhaokun]

@HeartSaVioR
Thanks for your reply,if possible, please help me merge it as soon as possible,because this PR has been created for a long time.