Adding in handling for secondary rate limit exceptions

Octokit.Tests/Http/ConnectionTests.cs

@@ -180,7 +180,7 @@ public async Task ThrowsApiValidationExceptionFor422Response()
             }
 
             [Fact]
-            public async Task ThrowsRateLimitExceededExceptionForForbidderResponse()
+            public async Task ThrowsRateLimitExceededExceptionForForbiddenResponse()
             {
                 var httpClient = Substitute.For<IHttpClient>();
                 var response = CreateResponse(
@@ -202,6 +202,28 @@ public async Task ThrowsRateLimitExceededExceptionForForbidderResponse()
                     exception.Message);
             }
 
+            [Fact]
+            public async Task ThrowsSecondaryRateLimitExceededExceptionForForbiddenResponse()
+            {
+                var httpClient = Substitute.For<IHttpClient>();
+                var response = CreateResponse(
+                    HttpStatusCode.Forbidden,
+                    "{\"message\":\"You have exceeded a secondary rate limit. Please wait a few minutes before you try again.\"}");
+
+                httpClient.Send(Args.Request, Args.CancellationToken).Returns(Task.FromResult(response));
+                var connection = new Connection(new ProductHeaderValue("OctokitTests"),
+                    _exampleUri,
+                    Substitute.For<ICredentialStore>(),
+                    httpClient,
+                    Substitute.For<IJsonSerializer>());
+
+                var exception = await Assert.ThrowsAsync<RateLimitExceededException>(
+                    () => connection.GetResponse<string>(new Uri("endpoint", UriKind.Relative)));
+
+                Assert.Equal("You have exceeded a secondary rate limit. Please wait a few minutes before you try again.",
+                    exception.Message);
+            }
+
             [Fact]
             public async Task ThrowsLoginAttemptsExceededExceptionForForbiddenResponse()
             {

Octokit/Http/Connection.cs

@@ -719,7 +719,7 @@ static Exception GetExceptionForForbidden(IResponse response)
         {
             string body = response.Body as string ?? "";
 
-            if (body.Contains("rate limit exceeded"))
+            if (body.Contains("rate limit exceeded") || body.Contains("secondary rate limit"))
             {
                 return new RateLimitExceededException(response);
             }