v1.3.0

• important changes:
  • improved and consequent support of RDF/JSON-LD. This means, an HDF5 can be created from a JSON-LD file and vice versa. The JSON-LD file
    contains the structural and contextual metadata of the HDF5 file.
  • namespaces are outsourced to ontolutils
• minor changes:
  • When a file is opened with a filename which does not exist and mode is None, the file will NOT be created. This was
    the case in the past, but this may lead to unwanted empty files.
  • Bugfix namespace creation
  • some method renaming and refactoring
  • accessors are refactored and improved (especially shifted away from xarray and fully integrated in hdf)