Merge branch 'master' of https://earth.bsc.es/gitlab/ces/c3s512-wp1-datachecker into master

* 'master' of https://earth.bsc.es/gitlab/ces/c3s512-wp1-datachecker:
  testing new json2txt_cdm
  Patch ini2pdf to handle inexistent key error when some ini lacks an specific section
  trying to use json library to avoid dependencies on json structure
  added check single-levels-2m_dewpoint_temperature-ncep-2.ini
  added check seasonal_original_single_levels-ncep-2-2m_temperature