SSH Configuration Util

[brainfunked]

SSH Configuration utility is needed, which implements the following methods, all invoked locally on a single node:

• Generate a key-pair for a user. The method can take the user name and key-pair name as optional parameters, whose defaults are root and tendrl respectively.
• Install an SSH key into a user's authorized_keys. SSH public key should be a mandatory parameter, while the user name should be optional. User name should default to root.
• Check if the SSH daemon is running and get it's port number.
• Check if the SSH incoming port is open.

[brainfunked]

Branch to send the PRs against: spec-141-ssh-utils. Branch on the specifications repository: https://github.com/Tendrl/specifications/tree/spec-141-ssh-utils.