coverage call dial-in details

Hi all

Anyone attending today's call (21:00UTC 12 April) should note the changed
webex dial-in details as noted on the meeting web page
https://www.w3.org/2015/spatial/wiki/Meetings:Coverage-Telecon20170412
(thanks Phil!)

The webex password for the call is probably something you can guess, if you
know that the last 3 letters are 'cov'

Bill