Call check_reqs before each script [i.e. via init]

Testing notes [Test the below scenarios on both Mac and Windows]
-Test calling check_reqs by itself to ensure that continues to work for CLI
-Test each platform script (build, run, clean etc) to ensure they continue to work.
-Test that each script calls the check_reqs successfully by calling them without bbndk on the path (or something similar) and verify an error is shown from the check_reqs script.