Add .lagoon.env environment files.

[steveworley]

• Adds a default .lagoon.env file to apply shield settings to Lagoon environments
• Adds a .lagoon.env.production to disable shield in Lagoon.

[tobybellwood]

I'm concerned that using a published default user and pass (even as a fallback) might inadvertently leave some sites exposed - it'd be better to tie it to something more obscure, but still easily discoverable to trusted users. Maybe not setting a fallback, and instead relying on the setting coming in during provisioning?

[stooit]

Can we also add docs that indicate what expected behaviour is (and how to determine user/pass).

I agree we shouldn't use published defaults, Ansible playbook should replace with something semi-random during provisioning?