First batch of updates to unit tests

- Remove content from __init__.py
- Change test_script_main to use pytest
- Update test_script_main to run on windows as well as linux

tests/__init__.py

@@ -1,18 +0,0 @@
-import sys
-import unittest
-
-
-def TestSuite():
-    suite = unittest.TestSuite()
-    loader = unittest.TestLoader()
-    if sys.platform == "win32":
-        from . import test_plat_win
-
-        suite.addTests(loader.loadTestsFromModule(test_plat_win))
-    else:
-        from . import test_script_main
-        from . import test_plat_other
-
-        suite.addTests(loader.loadTestsFromModule(test_script_main))
-        suite.addTests(loader.loadTestsFromModule(test_plat_other))
-    return suite