[BuildStream] Confirmation: changes to release schedule

[Laurence Urhegyi <laurence urhegyi codethink co uk>]

Hi,

During the gathering [0] in January this year and on this list prior to 
the event [1], we discussed and agreed a change to BuildStream's release 
model. I wanted to send this mail so that it could serve as formal 
confirmation what was agreed with that decision.

We are not going to be releasing version 1.4, and instead we are 
focusing all efforts on a new version of BuildStream, the current master 
branch, which will eventually stabilise and become version 2.0. Tristan 
outlines some of the reasons why in the recent blog post [2].

Version 2.0 will not be backwards compatible with the 1.x series of 
releases, but we are still aiming for a (mostly) compatible .bst file 
format, in order to make the transition as smooth as possible. We don't 
know when the new version will stabilise, and we purposely aren't 
committing to a date, but we don't expect this to be in 2019. We are 
therefore not actively working on 1.2, but will continue to make 
releases so long as bug-fixes are contributed and it is the only stable 
version available.

I'll also update the docs (probably the README) and the website.

Thanks,
Laurence

[0] 
https://docs.google.com/document/d/1bENn0gIHDPyTXaRwqSoA2F11gn55vvWLB7qMIe3Pk1U/edit#heading=h.hzgqfngiju
[1] 
https://mail.gnome.org/archives/buildstream-list/2019-January/msg00010.html
[2] 
https://blogs.gnome.org/tvb/2019/03/04/buildstream-news-and-2-0-planning/