update getAwsAuthToken to use parameters as object (#330)

* update getAwsAuthToken to use parameters as object

* update speech utils version

lib/utils/speech-utils.js

@@ -183,7 +183,10 @@ const testAwsStt = async(logger, getAwsAuthToken, credentials) => {
     } else if (roleArn) {
       client = new TranscribeClient({
         region,
-        credentials: await getAwsAuthToken(null, null, region, roleArn),
+        credentials: await getAwsAuthToken({
+          region,
+          roleArn
+        }),
       });
     } else {
       client = new TranscribeClient({region});