List pending organization / team invitations (#1640)

* 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

Octokit.Reactive/Clients/IObservableOrganizationMembersClient.cs

@@ -273,5 +273,28 @@ namespace Octokit.Reactive
         /// <param name="user">The login for the user</param>
         /// <returns></returns>
         IObservable<Unit> Conceal(string org, string user);
+
+        /// <summary>
+        /// List all pending invitations for the organization.
+        /// </summary>
+        /// <remarks>
+        /// See the <a href="https://developer.github.com/v3/orgs/members/#list-pending-organization-invitations">API Documentation</a>
+        /// for more information.
+        /// </remarks>
+        /// <param name="org">The login for the organization</param>
+        /// <returns></returns>
+        IObservable<OrganizationMembershipInvitation> GetAllPendingInvitations(string org);
+
+        /// <summary>
+        /// List all pending invitations for the organization.
+        /// </summary>
+        /// <remarks>
+        /// See the <a href="https://developer.github.com/v3/orgs/members/#list-pending-organization-invitations">API Documentation</a>
+        /// for more information.
+        /// </remarks>
+        /// <param name="org">The login for the organization</param>
+        /// <param name="options">Options to change API behaviour</param>
+        /// <returns></returns>
+        IObservable<OrganizationMembershipInvitation> GetAllPendingInvitations(string org, ApiOptions options);
     }
 }