Configure Fastly to log to S3 bucket

[chrisroos]

Fastly's default log format includes: timestamp, client_ip, geo_country, geo_city, host, url, request_method, request_protocol, request_referer, request_user_agent, response_state, response_status, response_reason, response_body_size, fastly_server, fastly_is_edge.

I suggest we remove client_ip as potential PII but retain everything else.

[chrisroos]

I've provided Marty with the ARN of the AWS IAM Role that has permission to write into an S3 bucket in the GFR AWS account. This is so that we can monitor the Fastly logs to determine which redirects we should put in place.