Add unit tests for calculator

calculator/bin/coverage3

@@ -0,0 +1,8 @@
+#!/lab/learning/python/Python_CI/calculator/bin/python
+# -*- coding: utf-8 -*-
+import re
+import sys
+from coverage.cmdline import main_deprecated
+if __name__ == '__main__':
+    sys.argv[0] = re.sub(r'(-script\.pyw|\.exe)?$', '', sys.argv[0])
+    sys.exit(main_deprecated())