security: ValidatorConfig rule evaluates all checkers

Also fix bug when target cert is not in anchors and cert cache is empty

Refs #3645

Change-Id: Ifb39e474c74611897ea28a1b8f26ed70750a1990
diff --git a/AUTHORS.md b/AUTHORS.md
index b837729..517b335 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -39,3 +39,4 @@
 * Marcin Juszkiewicz    <http://marcin.juszkiewicz.com.pl/>
 * Susmit Shannigrahi    <https://www.linkedin.com/in/susmit-shannigrahi-90433b8>
 * José Quevedo          <http://atnog.av.it.pt/members/jquevedo>
+* Zhiyi Zhang           <zhangzhiyi1919@cs.ucla.edu>