Made ElementEndpoint.ExistsAsync() throw on status codes other than 2xx, 404 or 410
Made ElementEndpoint.ExistsAsync() throw on status codes other than 2xx, 404 or 410

1and1/TypedRest-DotNet,TypedRest/TypedRest-DotNet,TypedRest/TypedRest-DotNet,1and1/TypedRest-DotNet