add async checkDNS

dist/smartacme.classes.acmecert.d.ts

@@ -57,9 +57,9 @@ export declare class AcmeCert {
      */
     requestChallenge(challengeTypeArg?: TChallengeType): q.Promise<ISmartAcmeChallengeAccepted>;
     /**
-     * checks if DNS records are set
+     * checks if DNS records are set, will go through a max of 30 cycles
      */
-    checkDns(): Promise<any>;
+    checkDns(cycleArg?: number): Promise<any>;
     /**
      * validates a challenge, only call after you have set the challenge at the expected location
      */