Fixes parent team removal, fixes the teams data source tests, adds tests for the parent team fix

[scott-doyland-burrows]

Resolves #1668
Resolves #1975

I have closed #1976 (which I initially setup) as this also resolves #1975 but is no longer needed as this PR will now fix it.

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Before the change?

#1668
Parent teams were created in terraform. However if a team was removed from the parent team then the statefile was updated, but the team still remained under a parent team in GitHub.

Also, if a team was removed from under a parent team in GitHub but still was defined in terraform, then terraform would not show a diff.

Overall, nested teams were not correctly managed by Terraform.

#1975
Before the change there was a failure reported in a test in the data_source_github_team_test.go file. The reason is the terraform data resource in the queries an existing team with connected repositories test block is only waiting on the github_team resource, and the data resource actually needs to wait on the github_team_repository resource.

Running this test:
TF_LOG=WARN TF_ACC=1 go test -v ./... -run ^TestAccGithubTeamDataSource
would result in a failure:

    testing.go:705: Step 0 error: Check failed: 3 errors occurred:
        	 Check 2/4 error: data.github_team.test: Attribute 'repositories_detailed.#' expected "1", got "0"
        	 Check 3/4 error: data.github_team.test: Attribute "repositories_detailed.0.repo_id" not set, but "repo_id" is set in github_repository.test as "708930695"
        	 Check 4/4 error: data.github_team.test: Attribute "repositories_detailed.0.role_name" not set, but "permission" is set in github_team_repository.test as "admin"

However, if using TF_LOG=DEBUG it would finish successfully - I believe this is just a timing issue. TF_LOG=DEBUG takes longer to run each resource, so by the time the data resource is actioned, the previous resources have all (just by chance) also completed.

It appears that the test for TestAccGithubTeamDataSource was defined incorrectly. I have refactored to bring the test in-line with how other tests are defined and this appears to have resolved the issue.

Formatting

The .tf files are now formatted correctly.

After the change?

Parent teams are correctly managed by Terraform. Tests have been defined and pass.

The data source tests for teams work.

Pull request checklist

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)

Does this introduce a breaking change?

Please see our docs on breaking changes to help!

• Yes
• No

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[kfcampbell]

This is great! Thank you for the thoughtful PR. All updated integration tests are passing for me as well.