Add support for Kerberos

[Dubrzr]

Hi,

Thank you for this awesome application!
Do you think it could be possible to make it work with kerberos auth?

Thank you!

[Dubrzr]

Ok, in the meantime I implemented the same hdfs-mount in Python with Kerberos:
https://github.com/Dubrzr/py-hdfs-mount
It works like a charm, I plan on implementing zip & avro support later.