GPU CI

[Krastanov]

Hi, Matias. I am setting up some GPU servers to use for CI and tests for the QuantumClifford org. I suspect it would be of use here as well.

If you are interested, I can set up a buildkite file for this repo.

I would suggest structuring the test file something like:

if get(ENV, "GPU_TEST", "")=="true"
    using Pkg
    Pkg.add("CUDA")
    include("test_gpu.jl")
else
    # other tests
end

If you want some fancier filtering, we can use something in this style: https://github.com/QuantumSavory/QuantumClifford.jl/blob/master/test/runtests.jl