Sanitize *auth* instead of authorization (elastic#573)

specs/agents/sanitization.md

@@ -16,7 +16,7 @@ how an agent will sanitize data.
 |                |   |
 |----------------|---|
 | Type           | `List<`[`WildcardMatcher`](../../tests/agents/json-specs/wildcard_matcher_tests.json)`>` |
-| Default        | `password, passwd, pwd, secret, *key, *token*, *session*, *credit*, *card*, authorization, set-cookie` |
+| Default        | `password, passwd, pwd, secret, *key, *token*, *session*, *credit*, *card*, *auth*, set-cookie` |
 | Dynamic        | `true` |
 | Central config | `true` |
 
@@ -47,4 +47,4 @@ body.  No fields (including `set-cookie` headers) are exempt from this.
 The query string and other captured request bodies (such as `application/json`)
 SHOULD NOT be sanitized.
 
-Agents SHOULD NOT sanitize fields based on the _value_ of a particular field.
+Agents SHOULD NOT sanitize fields based on the _value_ of a particular field.