new error for HTTP responses without stack trace (#1044)

* new error for HTTP responses without stack trace

* lint

lib/utils/error.js

@@ -17,8 +17,17 @@ class PlayFileNotFoundError extends NonFatalTaskError {
   }
 }
 
+class HTTPResponseError extends Error {
+  constructor(statusCode) {
+    super('Unexpected HTTP Response');
+    delete this.stack;
+    this.statusCode = statusCode;
+  }
+}
+
 module.exports = {
   SpeechCredentialError,
   NonFatalTaskError,
-  PlayFileNotFoundError
+  PlayFileNotFoundError,
+  HTTPResponseError
 };