Delay for 49 release to Sept. 20th

[Liz Henry (:lizzard)]

Hello Platform and Firefox teams,

Because of two blocking issues and the need for a bit more time to evaluate
the results of their fixes/backouts, we need to push back the upcoming
merge and release dates.

We will plan for merge day to be Monday Sept. 19th, with release planned
for Tuesday Sept. 20th.

50 will continue as aurora, and 51 as nightly for next week. The 50 beta
cycle was planned to be 8 weeks. We can afford to lose a week there and
still aim to ship 50 as scheduled.

We will need to build, test, and release a 49 RC3 (release candidate). I
may aim for an RC3 build tomorrow, with release next Monday, Sept. 12. We
also may wait to do the RC3 build on Monday for release the next day. Then
we will have several days to evaluate telemetry data and other criteria,
and have confidence we are shipping the best option to Firefox users.

You can see the current list of blocking and other issues in play, here:

https://public.etherpad-mozilla.org/p/49-blockers

Please let me know if you have feedback or any questions, by email or on
IRC on #release-drivers.


Best,

Liz


--
----
Liz Henry (:lizzard)
Firefox Release Manager
lhe...@mozilla.com