Low: cts: Test whether the Cibsecret test is applicable.

This test requires that a lab node can ssh into other lab nodes in order
to copy secret files around. If you haven't set up your ssh keys, ssh
will stop and prompt for a password which will eventually cause errors.
Instead, we can just test that one node can ssh into the others. This
is probably good enough as opposed to testing that every node can ssh
into every other.