* Add new AcceptsHeader
add Parent field to Team
add ParentId field to NewTeam and UpdateTeam
update Create Edit and Delete Team methods to use preview header
* Implement new API call GetAllChildTeams()
* Implement GetAllChildTeams for ObservableClient
* add integration test for observable client
* Add pagination tests for GetAllChildTeams
* Add NestedTeams preview header to all the API calls that use it
* Update tests for accepts header
* Add accepts header to observable client calls
* Fix DELETE implementation to use correct overload
* Fix tests - parent and child teams must be visibility Closed whereas the default if not specified is Private
* make sure all tests are flagged as [OrganizationTest]
* Make sure Update tests change the parent of the team
* Update new methods with NesterTeams preview API header and adjust tests
* Fixup TeamContext helper name
* Implement overload for GetAllMembers to take request parameter
* Update tests
* Implement Obersvable client changes
* Observable tests
* Implement AddOrEditMembership function returning a new response model, and obsolete the old AddMembership function returning an enum
* Implement GetMembershipDetails function returning new TeamMembershipDetails response model, and obsolete the old GetMembership function returning an enum
* Clarify that an exception is thrown when not a member
* Add integration tests for AddOrEditMembership and GetMembershipDetails
* fixup exception test for observable client
* Update wording of obsolete message
* Add methods for listing pending organization invites
* Add unit/integration tests
* Add methods for getting all pending invites for a team
* Add unit/integration tests
* 🔥 whitespace 🔥
* Move new enum to it's own correct file and location
* Invite(s) -> Invitation(s)
* Add helper functions for adding invitations and cleaning the invitations up at the end of the test
* Add methods with ApiOptions
* Fix helper methods for adding/removing invitations
* Forgot to actually pass in the ApiOptions to the API call
* Add tests for new ApiOptions methods
* tweak integration tests
* Update outside collaborator tests to use [OrganizationTest] attribute for consistency
* Update test accounts used
* use octokitnet-test2 account now it has 2FA turned on
