Implement GetOrCreateApplicationAuthentication

Implements the endpoint for creating an application authorization token.

Octokit/Exceptions/AuthorizationException.cs

@@ -34,3 +34,42 @@ namespace Octokit
 #endif
     }
 }
+
+
+/*
+            [Fact]
+            public void CreatesGitHubErrorFromJsonResponse()
+            {
+                var exception = new ApiUnauthorizedWebException("{\"message\":\"Bad credentials.\"}");
+
+                exception.ApiUnauthorizedError.Message.ShouldEqual("Bad credentials.");
+                exception.ApiUnauthorizedError.Errors.ShouldBeNull();
+            }
+
+            [Theory]
+            [InlineData("")]
+            [InlineData(null)]
+            [InlineData("{{{{{")]
+            public void CreatesGitHubErrorIfResponseMessageIsNotValidJson(string responseContent)
+            {
+                var exception = new ApiUnauthorizedWebException(responseContent);
+
+                exception.ApiUnauthorizedError.Message.ShouldEqual(responseContent);
+                Assert.False(exception.RequiresSecondFactor);
+            }
+
+            [Fact]
+            public void CanPopulateObjectFromSerializedData()
+            {
+                var exception = new ApiUnauthorizedWebException("{message:\"Bad credentials.\"}");
+                using (var stream = new MemoryStream())
+                {
+                    var formatter = new BinaryFormatter();
+                    formatter.Serialize(stream, exception);
+                    stream.Position = 0;
+                    var deserialized = (ApiUnauthorizedWebException)formatter.Deserialize(stream);
+                    deserialized.ApiUnauthorizedError.Message.ShouldEqual("Bad credentials.");
+                    exception.ApiUnauthorizedError.Errors.ShouldBeNull();
+                }
+            }
+*/

Octokit/Exceptions/TwoFactorChallengeFailedException.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace Octokit
+{
+#if !NETFX_CORE
+    [Serializable]
+#endif
+    public class TwoFactorChallengeFailedException : AuthorizationException
+    {
+        public TwoFactorChallengeFailedException()
+        {
+        }
+
+        public TwoFactorChallengeFailedException(string message) : base(message)
+        {
+        }
+
+        public TwoFactorChallengeFailedException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+#if !NETFX_CORE
+        protected TwoFactorChallengeFailedException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+#endif
+    }
+}

Octokit/Exceptions/TwoFactorRequiredException.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.Serialization;
+
+namespace Octokit
+{
+#if !NETFX_CORE
+    [Serializable]
+#endif
+    public class TwoFactorRequiredException : AuthorizationException
+    {
+        public TwoFactorRequiredException()
+        {
+        }
+
+        public TwoFactorRequiredException(string message) : base(message)
+        {
+        }
+
+        public TwoFactorRequiredException(string message, Exception innerException) : base(message, innerException)
+        {
+        }
+
+        public TwoFactorRequiredException(string message, TwoFactorType twoFactorType)
+            : base(message)
+        {
+            TwoFactorType = twoFactorType;
+        }
+
+#if !NETFX_CORE
+        protected TwoFactorRequiredException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+            if (info == null) return;
+            TwoFactorType = (TwoFactorType) (info.GetInt32("TwoFactorType"));
+        }
+
+        public override void GetObjectData(SerializationInfo info, StreamingContext context)
+        {
+            base.GetObjectData(info, context);
+            info.AddValue("TwoFactorType", TwoFactorType);
+        }
+#endif
+
+        public TwoFactorType TwoFactorType { get; private set; }
+    }
+
+    public enum TwoFactorType
+    {
+        None,
+        Unknown,
+        [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Sms")] Sms,
+        AuthenticatorApp
+    }
+}