Fix/986 (#990)

* throw new NonFatalTask error on play file not found

* linting

* make SpeechCredentialError subclass of NonFatalTask error

* cleanup

* Update action-hook-delay.js

* bump fsmrf version

* linting and package-lock

* Update package-lock.json

* update error

* only throw on fs error "File not found"

* add alert

* update time-series dep

* Update package-lock.json

* linting

* Update play.js

* remove stack trace from error message

* fix error formatting

lib/utils/error.js

@@ -1,9 +1,24 @@
-class SpeechCredentialError extends Error {
+class NonFatalTaskError extends Error {
   constructor(msg) {
     super(msg);
   }
 }
 
+class SpeechCredentialError extends NonFatalTaskError {
+  constructor(msg) {
+    super(msg);
+  }
+}
+
+class PlayFileNotFoundError extends NonFatalTaskError {
+  constructor(url) {
+    super('File not found');
+    this.url = url;
+  }
+}
+
 module.exports = {
-  SpeechCredentialError
+  SpeechCredentialError,
+  NonFatalTaskError,
+  PlayFileNotFoundError
 };