Merge pull request #588 from 94noni/patch-1

fix(doc): typo in the header name for Fastly

Author: dbu

doc/fastly-configuration.rst

@@ -13,7 +13,7 @@ Tagging
 ~~~~~~~
 
 Fastly supports cache tagging out of the box.
-Configure the tag header to ``Surrogate-Keys``. (``fos_http_cache.tags.response_header`` if you use FOSHttpCacheBundle)
+Configure the tag header to ``Surrogate-Key``. (``fos_http_cache.tags.response_header`` if you use FOSHttpCacheBundle)
 
 Purge
 ~~~~~