v1.2.0

• Added wait_max argument to retryhttp.wait_from_header and retryhttp.wait_retry_after, which defaults to 120.0 seconds.
• retryhttp._utils.is_rate_limited: revert behavior to correctly determine rate limiting by a 429 Too Many Requests` status.
• When receiving 503 Service Unavailable, honor a Retry-After header if provided.
• Rename retryhttp.wait_rate_limited to retryhttp.wait_retry_after, but retain alias for backwards compatibility and convenience.
• retryhttp.wait_from_header: Handle case if server responds with a date in the past.
• retryhttp.wait_context_aware: The wait_server_errors argument now defaults to retryhttp.wait_retry_after with tenacity.wait_random_exponential as fallback, since some server errors may respond with a Retry-After` header.
• retryhttp.wait_context_aware: The wait_rate_limited argument now has tenacity.wait_random_exponential as fallback to retryhttp.wait_retry_after, to make retrying rate-limited requests more robust.