Log Message:
(www/R-httpuv) Updated 1.6.9 to 1.6.11

# httpuv 1.6.11

* Fix race condition introduced in 1.6.10. (#363)

* Hygiene and metadata improvements requested by CRAN. (#366, #369, #370)

# httpuv 1.6.10

* WebSocket connections now send Ping frames to the client every 20
  seconds. This is only intended to serve as a keepalive for proxies
  that might be sitting in front of us; we don't pay attention to
  whether a Pong response is received in a timely manner. (#359)