fix acme prod setting detection

src/cert/acme.js

@@ -19,7 +19,10 @@ var CA_PROD = 'https://acme-v01.api.letsencrypt.org',
     LE_AGREEMENT = 'https://letsencrypt.org/documents/LE-SA-v1.0.1-July-27-2015.pdf';
 
 exports = module.exports = {
-    getCertificate: getCertificate
+    getCertificate: getCertificate,
+
+    // testing
+    _name: 'acme'
 };
 
 function AcmeError(reason, errorOrMessage) {

src/cert/caas.js

@@ -1,7 +1,10 @@
 'use strict';
 
 exports = module.exports = {
-    getCertificate: getCertificate
+    getCertificate: getCertificate,
+
+    // testing
+    _name: 'caas'
 };
 
 var assert = require('assert'),