`TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA`. This tracks a [Chromium
    change][remove_cbc_ecdsa] to remove these cipher suites because they are
    fragile and rarely-used.
 *  New: Don't fall back to common name (CN) verification for hostnames. This
    behavior was deprecated with RFC 2818 in May 2000 and was recently dropped
    from major web browsers.
 *  New: Honor the `Retry-After` response header. HTTP 503 (Unavailable)