RFE: Make admin_password, root_password, license optional

[andrewjjenkins]

In (e.g.) f5_supported/ve/standalone/f5_ve_standalone_3_nic.yaml, there are several required parameters. It would be great if:

• "license" was optional. Sometimes I might want to manually license my BIG-IP, especially if I'm deploying in a net that doesn't allow egress to the internet or I'm using F5 devkeys on the internet.
• Several of the auth parameters were optional. I like being able to specify admin_password and root_password, but I don't like being required to specify them. In AWS, BIG-IPs come up without an admin password and with the root account entirely disabled, so you can only log in using SSH key for admin@bigip. I like that. But I can totally understand why you might want to specify an admin_password; I just don't like being required to specify it. Same for root_password.

[swormke]

@andrewjjenkins I think one complication is that the heat template may be using the SDK which will require the REST API user/login. @pjbreaux can chat with you about what is required for the heat template to function and what isn't. But I agree if it is not needed for the heat template there is probably no reason we should be requiring it.