It is clear that reading of the holography observation in the test
data directory is supposed to be tested.  Hence just read it and
make sure that the content has been read correctly.

SW-43: fix avoid modification of the source dict while storing. Fixing iteration over the attribute and the values of the h5 dataset.

The test data is big.  Really big.  Too big to store it in a
source code repository.  This poses the problem that the test
has to either download it or to rely on the data being in a
defined location that is always on and always accessible from
everywhere.  Both solutions don't work in all cases.

Bottom line:  we have to figure this out!  For the time being the
test will just fail when the data is not in the expected location.

SSB-42: change script name to include .py extension and cmake script to rename the file when it installs it

expected