(QENG-1538) fixes EOS hack

In QENG-299, a hack was required to get around an issue w/EOS
for root ssh key setup.  A change was submitted to the
sshkeys repo to fix this.  This fix removes the hack, and
sets up the correct root ssh key procedure in Beaker for EOS

Conflicts:
	spec/beaker/host_prebuilt_steps_spec.rb