Update hadoop doc link to current (#244)
Update hadoop doc link to current (#244)

* Update hadoop doc link to current

The linked r2.7.2 section on passwordless ssh has outdated instructions using dsa.
Current docs show using rsa.

* address review comment - use specific version (r3.2.1)

Co-authored-by: Ed Coleman etcoleman <babc3c5a1cf883e8b38976f08df0256b6d9dfadf@apache.org>
astralway/uno,ctubbsii/fluo-dev