Add minimum supported libraries versions to the website

[RazrFalcon]

Currently, only >=2.42 is supported, but Travis CI uses Ubuntu 14.04 by default, which has 2.40. Is 2.42 mandatory or can we downgrade it a bit?

[EPashkin]

Travis has Xenial machines too: https://github.com/gtk-rs/sys/blob/master/.travis.yml#L1

[RazrFalcon]

Yes, but

uses Ubuntu 14.04 by default

[EPashkin]

But support 14.04 ends in this year: https://www.ubuntu.com/about/release-cycle

[RazrFalcon]

If 2.40 can't be supported by just lowering the minimum versions than it's fine.

Is there a list of minimal required versions for all gtk-rs crates?

[EPashkin]

Default versions is released with gtk3.14 (I don't have link)
others listed in https://github.com/gtk-rs/examples/blob/master/Cargo.toml#L25

[RazrFalcon]

I meant for all crates, like cairo, pango, etc. Yes, you can look in *-sys, but it's a bit troublesome.

[EPashkin]

Agree that we need table somewhere on https://gtk-rs.org/

[sdroege]

Can someone edit this issue? It should be about adding a table to the website about the minimum supported versions of the C libraries, and the latest version for which we have bindings right now.

@GuillaumeGomez ?