Locked Whoops to version 2.2.1

...until they fix that `[internal]` issue 
filp/whoops#598

Author: lcharette

CHANGELOG.md

@@ -5,6 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## v4.1.21
+- Locked Whoops to version 2.2.1 until they fix that [`[internal]` issue](https://github.com/filp/whoops/issues/598).
+
 ## v4.1.20
 - Added `route:list` command to list all registered routes ([#903](https://github.com/userfrosting/UserFrosting/pull/903); Thanks @apple314159 !)
 - Added warning in configuration file regarding disabling registration and email verification ([#900](https://github.com/userfrosting/UserFrosting/pull/900); Thanks @linkhousemedia !)

app/sprinkles/core/composer.json

@@ -13,7 +13,7 @@
     ],
     "require": {
         "doctrine/dbal": "^2.5",
-        "filp/whoops": "^2.1",
+        "filp/whoops": "~2.2.0",
         "illuminate/cache": "5.4.*",
         "illuminate/database": "5.4.*",
         "illuminate/events": "5.4.*",