Update clldutils to 3.19.0

[pyup-bot]

This PR updates clldutils from 3.10.1 to 3.19.0.

Changelog

3.18.1

Fixed a bug in `oaipmh` whereby OAI-PMH requests with resumptionToken would fail.

3.18.0

More versatile geocoords-to-string conversion in `clldutils.coordinates`.

3.17.0

- Vendor `paginate` package as `clldutils.paginate`, because the former has seen
no release since 2016.
- Vendor `webhelpers2.html` package as `clldutils.html`, because the former has seen
no release since 2015.
- Remove dependency on `csvw` for CSV reading in `iso_639_3`.

3.16.1

- Fixed bug whereby a missing command was **not** reported properly in the error message.

3.16.0

- Documentation overhaul.

3.15.1

- Fixed bug whereby OAI-PMH responses without resumption token would raise an error.

3.15.0

- Support for simple OAI-PMH harvesting.

3.14.0

- Better markdown link detection (on demand).

3.13.0

- Add functionality to strip TeX markup when instantiating a `Source` object.
- Allow passing keyword arguments through to `Source` from factory method `from_entry`.

3.12.0

- Added `clldutils.path.ensure_cmd` and `clldutils.text.replace_pattern`.
- Dropped support for py3.6.

3.11.1

- Fixed bug whereby a character preceding a markdown link would be stripped
when applying `MarkdownLink.replace`.

3.11.0

- Added support for manipulation of links in markdown text.

Links

• PyPI: https://pypi.org/project/clldutils
• Changelog: https://pyup.io/changelogs/clldutils/
• Repo: https://github.com/clld/clldutils