Make default username & password configurable

[afscrome]

Should also include a warning that the password is stored in cleartext

[afscrome]

Admin API key should also be configurable. (with an option to not set an API Key at all)

[RichMercer]

Perhaps we should only create the API key if requested. Most uses cases don't use it and it's probably better for security not to create them regardless. Some of these DB's might end up in production eventually.

[RichMercer]

The API key is now an optional parameter and isn't created by default.