Merge pull request #541 from mozilla/MP1556-deprecation-headers

fix(cors): add deprecation override to allowed headers

httpobs/website/decorators.py

@@ -91,6 +91,7 @@ def wrapper(*args, **kwargs):
                         'Access-Control-Allow-Origin': '*',
                         'Access-Control-Allow-Methods': ', '.join(request.url_rule.methods),
                         'Access-Control-Max-Age': '86400',
+                        'Access-Control-Allow-Headers': 'X-Deprecation-Override',
                     }
                 )