RFC: Proposing to freeze METADATA for package versions that support Julia 0.3

[Tony Kelman]

In the interest of moving nightly PackageEvaluator testing to running against 0.4, 0.5, and 0.6-dev, I'm proposing we freeze METADATA for Julia 0.3. New package versions that support Julia 0.3 would fail the Travis check, by default. We can make case-by-case exceptions if absolutely needed, but I believe this is the safest path forward to leaving Julia 0.3 alone - what currently works should remain working, and nothing new could break by releasing some new package versions that do support 0.3 when other packages that may depend on that package have moved on to only supporting Julia 0.4 a while ago.

If you're a package author, check the minimum Julia version dependency in your REQUIRE file. If it already says 0.4 or later, you don't need to do anything. If it still says 0.3, this change would mean you should raise the minimum Julia version to (at least) 0.4 before making your next tag. And when you make that new tag, since it's dropping Julia 0.3 support it should use a new package minor version via Pkg.tag("Foo", :minor).

If anyone has any comments or objections, let me know at https://github.com/JuliaLang/METADATA.jl/pull/6146. I'll be leaving that open for at least a few days.