templates: bug rendering record detail template due to edtf dates

[lnielsen]

The following code in record_landing_page.html does not support EDTF dates:

{{ record.publication_date|to_date|dateformat(format='long') }}

Example traceback:

Traceback (most recent call last):
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 2463, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/werkzeug/middleware/proxy_fix.py", line 232, in __call__
    return self.app(environ, start_response)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/werkzeug/middleware/dispatcher.py", line 66, in __call__
    return app(environ, start_response)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 2449, in wsgi_app
    response = self.handle_exception(e)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 1866, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 2446, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 1951, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 1820, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 1949, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/app.py", line 1935, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/invenio_records_ui/views.py", line 205, in record_view
    return view_method(pid, record, template=template, **kwargs)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/invenio_records_ui/views.py", line 227, in default_view_method
    record=record,
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/templating.py", line 140, in render_template
    ctx.app,
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/flask/templating.py", line 120, in _render
    rv = template.render(context)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/jinja2/environment.py", line 1090, in render
    self.environment.handle_exception()
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/jinja2/environment.py", line 832, in handle_exception
    reraise(*rewrite_traceback_stack(source=source))
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/jinja2/_compat.py", line 28, in reraise
    raise value.with_traceback(tb)
  File "/Users/lnielsen/src/invenio-rdm-records/invenio_rdm_records/theme/templates/invenio_rdm_records/record_landing_page.html", line 9, in top-level template code
    {%- extends config.BASE_TEMPLATE %}
  File "/Users/lnielsen/src/invenio-app-rdm/invenio_app_rdm/theme/templates/invenio_app_rdm/page.html", line 7, in top-level template code
    #}
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/invenio_theme/templates/invenio_theme/page.html", line 28, in top-level template code
    {%- endblock head_title %}
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/invenio_theme/templates/invenio_theme/page.html", line 31, in block "body"
    {%- if keywords %}<link rel="canonical" href="{{ canonical_url }}"/>{% endif %}
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/invenio_theme/templates/invenio_theme/page.html", line 32, in block "body_inner"
    {%- block head_links_langs %}
  File "/Users/lnielsen/src/invenio-rdm-records/invenio_rdm_records/theme/templates/invenio_rdm_records/record_landing_page.html", line 12, in block "page_body"
    {{ webpack['invenio-app-rdm-theme.css'] }}
  File "/Users/lnielsen/src/invenio-rdm-records/invenio_rdm_records/theme/templates/invenio_rdm_records/record_landing_page.html", line 13, in block "record_body"
    {{ webpack['invenio-rdm-records-theme.css'] }}
  File "/Users/lnielsen/src/invenio-rdm-records/invenio_rdm_records/theme/views.py", line 52, in to_date
    return arrow.get(date_string).date()
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/arrow/api.py", line 21, in get
    return _factory.get(*args, **kwargs)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/arrow/factory.py", line 196, in get
    dt = parser.DateTimeParser(locale).parse_iso(arg)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/arrow/parser.py", line 211, in parse_iso
    return self._parse_multiformat(datetime_string, formats)
  File "/Users/lnielsen/envs/cli/lib/python3.6/site-packages/arrow/parser.py", line 494, in _parse_multiformat
    string, ", ".join(formats)
arrow.parser.ParserError: Could not match input '1970-06-16/2003-12-05' to any of the following formats: YYYY-MM-DD, YYYY-M-DD, YYYY-M-D, YYYY/MM/DD, YYYY/M/DD, YYYY/M/D, YYYY.MM.DD, YYYY.M.DD, YYYY.M.D, YYYYMMDD, YYYY-DDDD, YYYYDDDD, YYYY-MM, YYYY/MM, YYYY.MM, YYYY