Implemented the rest of the User Administration Client and tests, including observable classes.

Octokit/Clients/UserAdministrationClient.cs

@@ -4,36 +4,83 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace Octokit.Clients
+namespace Octokit
 {
+    /// <summary>
+    /// A client for GitHub's User Administration API.
+    /// </summary>
+    /// <remarks>
+    /// See the <a href="https://developer.github.com/v3/users/administration/">Administration API documentation</a> for more details.
+    /// </remarks>
     public class UserAdministrationClient : ApiClient, IUserAdministrationClient
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UserAdministrationClient"/> class.
+        /// </summary>
+        /// <param name="apiConnection">The client's connection</param>
         public UserAdministrationClient(IApiConnection apiConnection)
             : base(apiConnection)
         {
         }
 
-        public Task Demote(string login)
-        {
-            throw new NotImplementedException();
-        }
-
+        /// <summary>
+        /// Promotes ordinary user to a site administrator.
+        /// </summary>
+        /// <remarks>
+        /// https://developer.github.com/v3/users/administration/#promote-an-ordinary-user-to-a-site-administrator
+        /// </remarks>
+        /// <param name="login">The user to promote to administrator.</param>
+        /// <returns></returns>
         public Task Promote(string login)
         {
             Ensure.ArgumentNotNullOrEmptyString(login, "login");
             var endpoint = ApiUrls.UserAdministration(login);
-
             return ApiConnection.Put(endpoint);
         }
 
-        public Task Suspend(string login)
+        /// <summary>
+        /// Demotes a site administrator to an ordinary user.
+        /// </summary>
+        /// <remarks>
+        /// https://developer.github.com/v3/users/administration/#demote-a-site-administrator-to-an-ordinary-user
+        /// </remarks>
+        /// <param name="login">The user to demote from administrator.</param>
+        /// <returns></returns>
+        public Task Demote(string login)
         {
-            throw new NotImplementedException();
+            Ensure.ArgumentNotNullOrEmptyString(login, "login");
+            var endpoint = ApiUrls.UserAdministration(login);
+            return ApiConnection.Delete(endpoint);
         }
 
+        /// <summary>
+        /// Suspends a user.
+        /// </summary>
+        /// <remarks>
+        /// https://developer.github.com/v3/users/administration/#suspend-a-user
+        /// </remarks>
+        /// <param name="login">The user to suspend.</param>
+        /// <returns></returns>
+        public Task Suspend(string login)
+        {
+            Ensure.ArgumentNotNullOrEmptyString(login, "login");
+            var endpoint = ApiUrls.UserSuspension(login);
+            return ApiConnection.Put(endpoint);
+        }
+
+        /// <summary>
+        /// Unsuspends a user.
+        /// </summary>
+        /// <remarks>
+        /// https://developer.github.com/v3/users/administration/#unsuspend-a-user
+        /// </remarks>
+        /// <param name="login">The user to unsuspend.</param>
+        /// <returns></returns>
         public Task Unsuspend(string login)
         {
-            throw new NotImplementedException();
+            Ensure.ArgumentNotNullOrEmptyString(login, "login");
+            var endpoint = ApiUrls.UserSuspension(login);
+            return ApiConnection.Delete(endpoint);
         }
     }
 }