change default value for asyncMode (#542)

* change default value for asyncMode

* update tests

Author: Edgar Cruzado

lib/test/TestSuite.js

@@ -167,9 +167,7 @@ class TestSuite {
      * @return {boolean} the async mode flag
      */
     get asyncMode() {
-        const defaultValue = ["phone", "twilio", "sms", "whatsapp"].includes(this.platform)
-            ? true
-            : false;
+        const defaultValue = true;
         return this.batchEnabled && Configuration.instance().value("asyncMode", this.configuration, defaultValue);
     }