Initial commit of changes required for an ssh feature. This is by no means a complete change.

More error checking, structural work and test cases to follow.

THIS SOFTWARE CONTRIBUTION IS PROVIDED BY THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED
- Fix failing unit test cases.
- switch from using
    dpkg-reconfigure openssh-server
    to
    ssh-keygen -t dsa -N "" -f /etc/ssh/ssh_host_dsa_key
    ssh-keygen -t rsa -N "" -f /etc/ssh/ssh_host_rsa_key
  dpkg-reconfigure often fails with random package manager errors. Plus ssh-keygen makes it more generic.

THIS SOFTWARE CONTRIBUTION IS PROVIDED BY THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED
- Remove TODO error checking. Looks as though run_script will throw an exception if the command fails.
- Adding new tests for ssh functionality.

THIS SOFTWARE CONTRIBUTION IS PROVIDED BY THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED
repointing to forked warden-test-infrastructure
Adding integration test for ssh functionality.

THIS SOFTWARE CONTRIBUTION IS PROVIDED BY THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED
Merge branch 'sshfeature'

THIS SOFTWARE CONTRIBUTION IS PROVIDED BY THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED