Remove 204-NoContent, Flask, and Werkzeug no longer provide

public apis to add additional error code exception handling.

puppetboard/app.py

@@ -17,7 +17,6 @@ from flask import (
 )
 
 from pypuppetdb import connect
-from pypuppetdb.errors import EmptyResponseError
 from pypuppetdb.QueryBuilder import *
 
 from puppetboard.forms import (CatalogForm, QueryForm)
@@ -119,26 +118,6 @@ def utility_processor():
     return dict(now=now)
 
 
-#
-# 204 doesn't have a mapping in werkzeug, we need to define a custom
-# class and then set it to the mappings.
-#
-class NoContent(ex.HTTPException):
-    code = 204
-    description = '<p>No content</p'
-
-abort.mapping[204] = NoContent
-
-try:
-    @app.errorhandler(204)
-    def no_content(e):
-        return '', 204
-except KeyError:
-    @app.errorhandler(EmptyResponseError)
-    def no_content(e):
-        return '', 204
-
-
 @app.errorhandler(400)
 def bad_request(e):
     envs = environments()