Minor fix for doc of client.AutoConfigClient
Minor fix for doc of client.AutoConfigClient

The current documentation states that HADOOP_PATH is used to determine additional
locations of configuration files. Instead HADOOP_HOME (and actually HADOOP_CONF_DIR, but
with this one I'm not sure if its consistently supported) is used. Also, it's worth
mentioning that core-site.xml is required for configuration as well to determine
default file-system name.

bolkedebruin/snakebite,spotify/snakebite,spotify/snakebite,aeroevan/snakebite,sbretzel/snakebite,bolkedebruin/snakebite,sbretzel/snakebite,ViaSat/snakebite,ViaSat/snakebite,aeroevan/snakebite