remove is_redirect

Author: marandaneto

text/0022-response-context.md

@@ -47,7 +47,6 @@ Adding it as part of the `Contexts`, we get a lot for free such as retained arbi
         "content-type": "text/html"
       },
       "status_code": 500,
-      "is_redirect": false,
       "body_size": 1000,
       "arbitrary_field": "arbitrary" // arbitrary and retained fields for backwards compatibility when adding new fields
     }
@@ -59,7 +58,6 @@ Adding it as part of the `Contexts`, we get a lot for free such as retained arbi
 * `cookies`: Can be given unparsed as `String`, as `Dictionary`, or as a `List of Tuples`.
 * `headers`: A `Dictionary` of submitted headers, this requires a special treatment in the data scrubbing rules.
 * `status_code`: The HTTP status code, `Integer`.
-* `is_redirect`: A `Boolean` indicating if the response was a redirect.
 * `body_size`: A `Number` (absolute/positive) indicating the size of the response body in bytes.
 
 The `url`, `method`, `query_string`, `fragment`, `env` fields are not part of the `Response` interface and they should be set under the `Request` field, even if inferred from the HTTP response in case you don't have control over the HTTP Request object.