Grape helper passes doorkeeper headers to error

From https://github.com/intridea/grape#headers:

> When raising error!, pass additional headers as arguments.
>   error! 'Unauthorized', 401, 'X-Error-Detail' => 'Invalid token.'

[fixes #682]

Author: djordje

NEWS.md

@@ -10,6 +10,7 @@ User-visible changes worth mentioning.
   the /oauth/token path. Switch from using a DateTime object to update
   AR to using a Time object. (Issue #668)
 - [#677] Support editing application-specific scopes via the standard forms.
+- [#682] Pass error hash to Grape `error!`
 
 ## 3.0.0 (rc1)
 

lib/doorkeeper/grape/helpers.rb

@@ -26,7 +26,7 @@ def doorkeeper_render_error_with(error)
                         403
                       end
 
-        error!({ error: error.description }, status_code)
+        error!({ error: error.description }, status_code, error.headers)
       end
 
       private