Documentation clarification for [cluster.mycluster] section configuration

[Daniel314]

Would it be possible to add a note to the documentation about cluster names in the config file?

I found out the hard way that if the cluster name has upper-case characters in it, it breaks things? (Specifically, the burrow program will report "unknown cluster" (in the addConsumerOffset() routine) for all consumer offset updates with a cluster name of "CMU" or "Cmu". It works fine with a cluster name of "cmu")

Here is an example log error message when the cluster name has an upper-case letter in it: {"level":"warn","ts":1517431581.178074,"msg":"unknown cluster","type":"module","coordinator":"storage","class":"inmemory","name":"default","worker":11,"cluster":"Cmu","consumer":"test","topic":"LSpipeline","partition":58,"topic_partition_count":0,"offset":1827590082,"timestamp":1517431580904,"owner":"","request":"StorageSetConsumerOffset"}

Thank you,

- Daniel