Add new resource github_team_members to allow authoritative team management

[stawik-mesa]

Relates to #395

Add new resource to allow authoritative team memberships.

Usage:

resource "github_team_members" "test_team_memberships" {
  team_id  = github_team.test_team.id
  members {
    username = "octocat"
    role     = "member"
  }

  members {
    username = "octocat2"
    role     = "maintainer"
  }
}

[majormoses]

I like the idea, I am not sure if the name should be so similar that someone might accidentally typo the wrong one. Maybe something more explicit would be better as this deviates from the 1:1 relationship we have with the api to resource now.

Some suggestions, feel free to mix/match as I could not say I found a name I loved:

• github_team_membership_removes_undefined
• github_team_members_remove_unmanaged
• github_group_only_these_members
• github_group_remove_unmanaged_users
• github_group_terraform_managed_only

[stawik-mesa]

Do you really think it's necessary to such a long name?

I would prefer github_team_members (differs from github_team_membership).

I also added a detailed description in the resource documentation.

[jcudit]

I think this resource would make the overall use case much easier to configure, but dilutes the project slightly with yet another way to accomplish the task.

As for naming, I wish github_team_membership was already available or github_team could have taken the members block. I'm open to not block on the naming if we can get clearer documentation around when to use this resource versus the others.

Finally, the tests need to be reworked slightly to match the existing pattern. See resource_github_team_test for a relevant example, particularly the anonymous / individual / organization casing.

[stawik-mesa]

@jcudit Thanks for the comments. I updates the documentation and reworked the test case.

[jcudit]

Gave this a spin locally but found it difficult to test given the whole invite-another-collaborator flow. Looks good on another read through though and feel we can ship and iterate if needed.

🙇🏾 for the docs updates, hoping they reduce confusion over time.

[stawik-mesa]

@jcudit Do you already have a timeline for the merge? Thanks for the reviews and approval ;)

[kfcampbell]

@jcudit and I have read through this together and we'll get it released shortly!