[spaceship] add update method to ConnectAPI::User

[nekrich]

Checklist

• I've run bundle exec rspec from the root directory to see all new and existing tests pass
• I've followed the fastlane code style and run bundle exec rubocop -a to ensure the code style is valid
• I see several green ci/circleci builds in the "All checks have passed" section of my PR (connect CircleCI to GitHub if not)
• I've read the Contribution Guidelines
• I've updated the documentation if necessary.

Motivation and Context

We want to have the ability to change user roles and app access. And for that, we need Modify a User Account
API implemented.

Description

• Add a new request to update user. We can modify the User instance and just execute update or describe changes using parameters.
• Fix UserInvitation.create docs.
• Remove relationships for User.update & UserInvitation.requests if all apps are allowed to reduce the number of API errors.

Testing Steps

users = Spaceship::ConnectAPI::User.all
users.first.update(provisioning_allowed: false, roles: ['SALES'])

last_user = users.last
last_user.provisioning_allowed = false
last_user.roles = ['SALES', 'DEVELOPER']
last_user.update

[nekrich]

@revolter , sorry for the ping, but if there is something I can improve?

[nekrich]

@joshdholtz , do I have any chances you review this PR🙏 ?

[nekrich]

@ainame , @rogerluan , any kind of feedback is appreciated 🙏 .

[rogerluan]

Overall LGTM! Left some questions though 🙏

Thank you for this contribution @nekrich !

[revolter]

Unfortunately, I don't have experience with this part of the app, so I can't say much (except some nitpicking) 😞

All the changes do make sense to me, though, and I trust that you actually tested them 💪🏻

Also, it doesn't look like it could break anything, but I'm not sure, so I'd wait for @joshdholtz to take a look too 😟

[nekrich]

Any chances of merging this?

[revolter]

I took another look, and, again, it doesn't look like it could break existing logic, it rather adds new logic, so I will merge this.