Pass GOVUK-Request-Id header on api interaction

https://github.com/alphagov/gds-api-adapters?#middleware-for-request-tracing
Log GOVUK-Request-Id header
Merge pull request #1189 from alphagov/log_govuk_request_id

Log GOVUK-Request-Id header
Merge pull request #1187 from alphagov/pass-on-GOVUK-Request-Id-on-api-calls

Pass GOVUK-Request-Id header on api interaction