Bug in generated spec .json

[baranna]

Title

In SigSpec.AspNetCore the generated spec.json file always adds new type definitions if you keep refreshing the page

Steps to reproduce

1. Start HelloSignalR sample project
2. Go to /sigpsec/v1/sigspec.json
3. Refresh the page (one or more times)

Current behaviour

New definitions are generated at each refresh (Person, Person2, Person3....)

Expected behaviour

The spec doesn't change at refresh

Screenshot

[RicoSuter]

I think this is fixed but not released yet.