Improve testing

[BaptisteVandecrux]

Hey @ladsmund & @PennyHow ,

It would be great if we could:

• have the name of the test printed out in stdout before either a message for success or the eventual error message. Right now it is very time consuming to know which test triggered the error.

• find better names for process_test.yml and test_process.py which is a unit test?

• At the moment the unit test test_l0_to_l3 in test_process.py prints out errors linked to the absence of station_configuration files and due to insufficient info to process surface height. Instead of maintaining test input files and test config files (which need to be maintained anytime there is an update), we could use few sites and clone AWS-L0 like it is done in process_test.yml.

• There are still a lot of errors thrown by the BUFR-related tests, but they do not prevent the merge. @ladsmund I believe that they are already on develop so I'll merge the surface height branch and we'll need to address them at a later point.

• make a test_join_l2

• make a test_get_l2tol3

• make a test_join_l3

• make a test_make_metadata_csv