Build with both devel and latest stable versions of Nim.

[wizzardx]

Lots of packages are failing to build now on the CI service, since they depend on nim devel to build, rather than nim stable.

Maybe the CI service can intelligently pick which version of Nim to build with, and switch to that with choosenim?

[FedericoCeratto]

Initially I tried building twice but the benefits are unclear: the developers often do not provide hints on requiring Nim devel.
Any new thoughts after Nim 1.0.0 has been released? Ping @Araq @narimiran

[narimiran]

IMO, now that 1.0 is out, packages should be tested against the (latest) stable version, and they should depend on either the latest or some previous stable version.

[Araq]

As many packages as possible should work with 1.0, you can in addition to that also test against "Nim devel".