Test functions over-report warnings

[teddychao]

Test functions seem to report two kinds of abnormalities in any case

1. Verification failed in XX due to The function handle did not issue any warnings.
2. Error occurred in XX and it did not run to completion.

Not sure if the first situation is encouraged. If no warning is generated, it may be running as expected, thus the command window can remain silent to avoid over-reporting.

[teddychao]

Many test functions seem not modified from the template load_data. I am not sure if all test functions are currently working. I would suggest to revise all the test functions.

[teddychao]

The issue has been resolved in a recent update of test functions.