Features/auto qc

[ladsmund]

I have done some restructuring of the repository and created a qc module that can contain different algorithms for detecting invalid data.

[PennyHow]

I've just left a few comments regarding structure and naming conventions. I've also been testing the functionality of the QC steps and I am running into problems. Some of these might be to do with both of these QC development branches not being up-to-date with the main branch.

So I think it is best to addres the minor issues I have commented on, then merge, and then we can do a larger review over on percentile-qc.

Just so you have a heads up @RasmusBahbah, I'm having problems in the script creating a database .db file if one does not already exist. We can look at it once this branch has been merged.

[PennyHow]

Looks good. I just checked the unit testing and then tested it with some L0tx and L0raw files. All runs smoothly. Go ahead and merge.

[PennyHow]

I think this file needs some extra lines adding at the end so that the unit test is triggered when the script is run, i.e.:

if __name__ == "__main__":  
    unittest.main()

[PennyHow]

Documentation needed for each function here - it can just be a short definition, for example:

def get_random_datetime() -> datetime.datetime:
   '''Select random timestamp in the period `1970-2030'''

[PennyHow]

I think the submodule file names need changing as the naming style does not fit with the rest of the toolbox. I suggest:

compute_percentiles.py and percentiles.py >> percentile.py
static_qc.py >> persistence.py
static_qc_test.py >> persistence_test.py

Also, I suggest a structuring change in the qc module initialization:

from pypromice.qc.percentile import *
from pypromice.qc.persistence import *

Then we can call, for instance, percentileQC merely with pypromice.qc.percentileQC rather than pypromice.qc.percentile.percentileQC. I think if this module becomes bigger, then submodule divisions will be needed. But for now, the functions are very streamlined (nice!)

[PennyHow]

I prefer calling this a persistence QC rather than a static QC, as 'static' is an ambiguous term. So perhaps rename these functions to, e.g. persistence_qc()?