test-launcher is run from build/bin directory, not install bin directory

[jeff-cohere]

When one uses EkatCreateUnitTest to create a unit test, EKAT uses a script called test-launcher to launch the test. However, EkatCreateUnitTest assumes that it can find test-launcher in the bin subdirectory of your build directory. This is only true if you're building EKAT with add_subdirectory. It will not work if you've installed EKAT somewhere already.

To Reproduce
Steps to reproduce the behavior:

1. Build EKAT and install it somewhere
2. Build your EKAT-dependent software, pointing it to the installed version of EKAT
3. Try to run unit tests created using EkatCreateUnitTest. They will all fail because test-launcher can't be found.

Expected behavior
It would be nice to have EKAT install test-launcher in the bin subdirectory of its CMAKE_INSTALL_PREFIX.

[jeff-cohere]

Hrmm, maybe never mind. Let me verify this.

[bartgol]

I think this will become a non-issue, as soon as #179 is merged. I am holding off the merge, since I need to work on a PR that ensures the same capabilities are kept in scream.

[bartgol]

Actually, coming to think of it, we might keep test-launcher in ekat. Just not add it by default to the command to be run by add_test. There's some logic in ekat_catch_main.cpp to handle the selection of the GPU, and test-launcher is already doing some of that work if the proper test properties have been set (and our EkatCreateUnitTest[xyz] do set them).

I will make a not to keep the test-launcher. In which case, if you verify this is indeed an issue, we should address it.

[jeff-cohere]

Okay, sounds good. I think it might not actually be an issue after all, but I will verify.