Log user authentication

auth/auth.go

@@ -82,6 +82,10 @@ func Require(next http.Handler, authFailed http.Handler, provider Provider) http
 			return
 		}
 
+		log.Get(r).
+			WithField("user", *user).
+			Info("user authenticated")
+
 		key := contextKey("user")
 		ctx := context.WithValue(r.Context(), key, *user)