MACOBAC csv files changed format

Due to the volcanic eruption in Mauna Loa in November, the scientific station where the CO2 measurements were taking place is closed. The measurements, after an interruption, are continuing (temporarily?) at the nearby Mauna Kea. Due to that, a new field with the measurement station was added in the csv file. This resulted in breaking our tests.

The bug can be fixed rather easily, however we might want to think in the future of a more robust way to analyse the file.

Another thing to do would be to decompose the MACOBAC tests. Right now we have 2 tests:

• One tests the downloading and reading of the file
• The other ensures that the calculation of the CO2 bkg concentration is not broken

I propose to split the first test in one solely for downloading and a second for reading. This we can do in the framework of level-c decomposition.