Removed keypair generation for user hadoop.
Removed keypair generation for user hadoop.

keypair is generated from the vanilla plugin now.

Partially implements: blueprint avoid-keypair-in-dib-scripts
Fixes: bug #1188442

Change-Id: I1df0d436cf80885ef5b66ad7b2aa46b691e7dca8

openstack/sahara-extra,openstack/sahara-extra,openstack/sahara-extra,openstack/sahara-extra