Use pre-releases for Fortress

[chapulina]

Removed nightlies from all libs above ign-gazebo, and appended it for the ones below

gazebo-tooling/release-tools#459

[azeey]

Removed nightlies from all libs above ign-gazebo, and appended it for the ones below

Not sure what above and below mean in this context, would it not work if all of them had all three repos?

[chapulina]

Not sure what above and below mean in this context,

Sorry, by above I meant upstream. We already have pre-releases up to ign-gui and ign-physics, so the only libs that still need nightlies are ign-gazebo, ign-launch and ignition-fortress.

would it not work if all of them had all three repos?

It may, but mixing up pre-releases and nightlies may have unintended consequences that I'd like to avoid as much as possible

[azeey]

I see. Thanks for the explanation.