Include build scripts for c++ solvers in tests

[AnderGray]

Package was failing when testing on my HPC machine, and getting a confusing error from Julia.

Eventually found it was the c++ external solvers used in some of the tests

i.e this one: https://github.com/FriesischScott/UncertaintyQuantification.jl/blob/e62374b006d449b8e8b5a0a4aa0fc4a356d6da57/test/solvers/src/radius.c#L1

Perhaps it's worth including little build script for these c++ external solvers, and printing a custom error message in the case that these tests fail.

[FriesischScott]

Hey, thanks for reporting this. I think it would be good to potential move away from these compiled solvers. I see two potential solutions:

• Use a simple shell script radius.sh on unix machines and radius.ps1 on windows machines.
• Use a standalone Julia script that can do this without needing any extra dependencies.

Any preferences?

[AnderGray]

I find the 100% Julia solution to be the cleanest, unless it defeats the purpose of the external model test?

[FriesischScott]

As long as I call it as a separate process it should't be a problem. I'll see what can be done.