Parsing of cells from markdown document is broken

[smathot]

When trying to run a code cell from a Markdown document, the following Exception occurs.

Traceback:
  File "/usr/lib/python3/dist-packages/libqtopensesame/extensions/_extension_manager.py", line 199, in provide
    return ext.provide(provide, **kwdict)
  File "/usr/lib/python3/dist-packages/libqtopensesame/misc/base_subcomponent.py", line 100, in provide
    return getattr(self, u'provide_%s' % provide)(**kwdict)
  File "/usr/share/opensesame_extensions/JupyterNotebook/JupyterNotebook.py", line 103, in provide_jupyter_notebook_cells
    return getattr(m, 'parse_{}'.format(language))(code, cell_types)
AttributeError: module 'jupyter_notebook_cell_parsers.parse_markdown' has no attribute 'parse_markdown'