Issue253 coverage (#557)

[mwetter]

This closes #253

• add coverage script from Mans with changes based on review in Issue253 testexamplescoverage #315 Issue234 jmodelica regression #243

• add unit-test and fix minor bug

• Catch case for no examples

[mwetter]

@FWuellhorst : Can you please correct the doctests, see https://app.travis-ci.com/github/lbl-srg/BuildingsPy/builds/271076330#L695
and also update the CHANGES.txt file.

I already merged #562 into this branch to avoid a merge conflict.

[FWuellhorst]

@mwetter I fixed the test and added to the Changes.txt.

Another question: Using the latest buildingspy, you seemed to add a statement which prevents .mat files being copied to the tmp folder. We use .mat files for weather data in some regression tests in AixLib, leading to failing tests with no error indication, used "False". I had to use docker with port-forwarding to track down the issue. We could switch to txt or mos, but CombiTables support .mat. Why did you opt to not copy .mat files?

[mwetter]

@FWuellhorst : We excluded *.mat files to make sure that no old result files are copied, and to reduce time for copying/disk space if someone runs regression tests multiple times as there can be more than 1000 .mat files from old runs, some of them being quite large.
If we were to allow copying mat files in certain directories, the best may be to search for them with glob and copy them. Currently the library is copied with shutil.copytree which allows excluding files but I don't think it allows excluding files if they are in a specific directory.

[FWuellhorst]

That makes sense. I converted them to .txt, which is either way better for git. Thanks!

[mwetter]

@FWuellhorst : FYI, this is now merged.