Ability to not remember username and password

[max-wittig]

Thanks for creating this nice tooling!

For automation purposes, I was wondering if it would be possible to add an environment variable like XCODES_REMEMBER_CREDENTIALS. This one could then be set to false to not save it into the keychain. I know that I can also call signout so its just a suggestion.

Let me know, what you think!

[epau]

+1. was just scouring the docs looking for a feature like this.