add the ability to use various user, pass, login_user, login_pass,ssh_keys, sudo and sudo_password and sudo_options elements

[aaronlippold]

If we were going to try to run a few of the more complex profiles, such as the https://github.com/CrunchyData/pgstigcheck-inspec profile, we would have to be able to pass the following meta-data to the runner:

inspec exec pgstigcheck-inspec --input_files inputs.yml -i <your ssh private key> --sudo --sudo-options="-u postgres" -t ssh://<user>@<db host>:<port>

Given that we are connecting to the host as either root or the login_user but then scanning the RDMS via using sudo to switch to the postgres user.