added check_edtf_level_0 to check publication_date for zenodo format
Until now deploy2zenodo accepts everything for uploading. Unfortunately the publication_date
has to be in a certain format (see Publication date). zenodo does not check this. Uploading a wrong format leads to an unreachable zenodo record.
deploy2zenodo
tries now to do a simple check.
This merge request closes #1 (closed).