Specified cast not valid when retrieving events

[devdigital]

When I run the following unit test:

[Fact]
public void Test()
{
    var github = new GitHubClient(new ProductHeaderValue("MyApp"));
    var events = github.Activity.Events.GetUserPerformed("myuser").Result;
}

I get a casting exception because the first event that is returned as JSON has an id value which contains surrounding speech marks, and when it tries to populate the integer Id property of the Activity type, the exception occurs.