Dropwizard 0.8.0-rc1 error with OAuthFactory

OAuthTest.java

package bo.gotthardt.oauth2;

import com.google.common.base.Optional;
import io.dropwizard.auth.Auth;
import io.dropwizard.auth.AuthFactory;
import io.dropwizard.auth.AuthenticationException;
import io.dropwizard.auth.Authenticator;
import io.dropwizard.auth.oauth.OAuthFactory;
import io.dropwizard.testing.junit.ResourceTestRule;
import org.junit.ClassRule;
import org.junit.Test;

import javax.ws.rs.GET;
import javax.ws.rs.Path;

public class OAuthTest {
    @ClassRule
    public static final ResourceTestRule resources = ResourceTestRule.builder()
            .addResource(new DemoResource())
            .addResource(AuthFactory.binder(new OAuthFactory<>(new DemoAuthenticator(), "demo", String.class)))
            .build();

    @Test
    public void test() {
        // Will throw a NullPointerException in OAuthFactory#provide() due to request being null.
        resources.client().target("/demo/hello").request().get();
    }

    @Path("/demo")
    public static class DemoResource {
        @GET
        @Path("/hello")
        public String test(@Auth String username) {
            return "Hello " + username;
        }
    }

    public static class DemoAuthenticator implements Authenticator<String, String> {
        @Override
        public Optional<String> authenticate(String credentials) throws AuthenticationException {
            return Optional.of("world");
        }
    }
}