Release v0.24 - A Sight For Sore Eyes (#1539)

* Add release notes and bump version to 0.24

* run "build FormatCode" to fix up whitespace/formatting issues

* Fix failing Ssh key tests due to "validation exception".  This key must be in use on github (under another user, most likely from these tests failing).  Changed to a new SSH key and tweaked tests to reduce chance of a key being created and not destroyed

* Assignee and Assignees cant both be specified on NewIssue.  We missed this one in the PR.  Marked Assignee as [Obsolete] and fixed tests to use Assignees

* Fix a couple of Reactions tests that were calling the wrong client methods

* Fix timeline tests - looks like the response class has changed shape a bit, it now has an Issue object in the payload and Id field isnt present (leaving Id field there in case other timeline events do use it)

* Fix some following tests that require the test user to follow more than 1 other user

* Unskip these Event tests now because apparently they work!

* add breaking changes notes

* Update ApiErrorMessageSafe to return null for empty and whitespace strings (#1540)

* return null if ApiError.Message is empty or whitespace

* Uncomment test, which now passes

* update release notes to include PR1540

* Add "Bot" AccountType, was causing a deserialization exception when running the integration test "SearchForExcludedLanguage" (#1541)

* Update to include PR1541

* add bullets to make release notes easier to read

* markup additional code mentions in notes

* Fix grammar

fields => field

Octokit.Tests.Integration/Helpers/ObservableGithubClientExtensions.cs

@@ -46,7 +46,7 @@ namespace Octokit.Tests.Integration.Helpers
         {
             // Create a key
             string keyTitle = "title";
-            string keyData = "ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAQEAjo4DqFKg8dOxiz/yjypmN1A4itU5QOStyYrfOFuTinesU/2zm9hqxJ5BctIhgtSHJ5foxkhsiBji0qrUg73Q25BThgNg8YFE8njr4EwjmqSqW13akx/zLV0GFFU0SdJ2F6rBldhi93lMnl0ex9swBqa3eLTY8C+HQGBI6MQUMw+BKp0oFkz87Kv+Pfp6lt/Uo32ejSxML1PT5hTH5n+fyl0ied+sRmPGZWmWoHB5Bc9mox7lB6I6A/ZgjtBqbEEn4HQ2/6vp4ojKfSgA4Mm7XMu0bZzX0itKjH1QWD9Lr5apV1cmZsj49Xf8SHucTtH+bq98hb8OOXEGFzplwsX2MQ==";
+            string keyData = "ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAQEAq42HufbSy1BUbZTdKyEy8nX44gdchbh1A/cYuVFkRXETrFr6XYLETi4tauXGS3Wp3E4s3oG272O4JW+fIBX0kuOJXnRgYz52H3BDk6aY9B0ny+PYFJrYrpG43px5EVfojj9o7oxugNq4zLCGqWTqZU1maTf5T4Mopjt0ggA7cyNnM5B645cBxXjD2KNfrTIyLI+meYxptzjRiB6fHLGFRA9fxpVqUnbq7EcGbwsTlILRuEPt58hZ9He88M45m0F8rkVZOewt4JSzsLsC+sQs+h/LXI8dbrg6xWpxJVi0trzYuMuY/MwygloWKtaFQYuPkJ7yqMZ3Aew+J3DupF6uxQ==";
 
             var key = await client.User.GitSshKey.Create(new NewPublicKey(keyTitle, keyData));