OAuthBearerAuthenticationNotifications.SecurityTokenValidated is never triggered

[kevinchalet]

https://github.com/aspnet/Security/blob/dev/src/Microsoft.AspNet.Security.OAuthBearer/OAuthBearerAuthenticationHandler.cs#L134-L148

/cc @brentschmaltz @Tratcher

[brentschmaltz]

Thanks.

[kevinchalet]

@brentschmaltz I'm preparing a PR for that. The fix is really trivial but I realized that the OAuth2 Bearer middleware tests weren't not totally effective (they just check if the response status code is 200).

[kevinchalet]

Here we go: #168

[HaoK]

Merged 4a2a742