Unit test infrastructure setup

[mwaxmonsky]

Originator(s): @mwaxmonsky

Summary (include the keyword ['closes', 'fixes', 'resolves'] and issue number): Sets up the basic infrastructure to start enabling unit testing. Addresses #82

Describe any changes made to the namelist: N/A

List all files eliminated and why: N/A

List all files added and what they do:
A .github/workflows/code-coverage.yaml
A test/unit-test/CMakeLists.txt
A test/unit-test/include/ccpp_kinds.F90
A test/unit-test/tests/CMakeLists.txt
A test/unit-test/tests/utilities/CMakeLists.txt
A test/unit-test/tests/utilities/test_state_converters.pf

• Initial round of infrastructure to start enabling unit tests.

List all existing files that have been modified, and describe the changes: N/A
(Helpful git command: git diff --name-status development...<your_branch_name>)

List any test failures: N/A

Is this a science-changing update? New physics package, algorithm change, tuning changes, etc? No