Update beautifulsoup4 to 4.7.1

[pyup-bot]

This PR updates beautifulsoup4 from 4.6.0 to 4.7.1.

Changelog

4.6.2

* Fix an exception when a custom formatter was asked to format a void
element. [bug=1784408]

4.6.1

* Stop data loss when encountering an empty numeric entity, and
possibly in other cases.  Thanks to tos.kamiya for the fix. [bug=1698503]

* Preserve XML namespaces introduced inside an XML document, not just
the ones introduced at the top level. [bug=1718787]

* Added a new formatter, "html5", which represents void elements
as "<element>" rather than "<element/>".  [bug=1716272]

* Fixed a problem where the html.parser tree builder interpreted
a string like "&foo " as the character entity "&foo;"  [bug=1728706]

* Correctly handle invalid HTML numeric character entities like &147;
which reference code points that are not Unicode code points. Note
that this is only fixed when Beautiful Soup is used with the
html.parser parser -- html5lib already worked and I couldn't fix it
with lxml.  [bug=1782933]

* Improved the warning given when no parser is specified. [bug=1780571]

* When markup contains duplicate elements, a select() call that
includes multiple match clauses will match all relevant
elements. [bug=1770596]

* Fixed code that was causing deprecation warnings in recent Python 3
versions. Includes a patch from Ville Skyttä. [bug=1778909] [bug=1689496]

* Fixed a Windows crash in diagnose() when checking whether a long
markup string is a filename. [bug=1737121]

* Stopped HTMLParser from raising an exception in very rare cases of
bad markup. [bug=1708831]

* Fixed a bug where find_all() was not working when asked to find a
tag with a namespaced name in an XML document that was parsed as
HTML. [bug=1723783]

* You can get finer control over formatting by subclassing
bs4.element.Formatter and passing a Formatter instance into (e.g.)
encode(). [bug=1716272]

* You can pass a dictionary of `attrs` into
BeautifulSoup.new_tag. This makes it possible to create a tag with
an attribute like 'name' that would otherwise be masked by another
argument of new_tag. [bug=1779276]

* Clarified the deprecation warning when accessing tag.fooTag, to cover
the possibility that you might really have been looking for a tag
called 'fooTag'.

Links

• PyPI: https://pypi.org/project/beautifulsoup4
• Changelog: https://pyup.io/changelogs/beautifulsoup4/
• Homepage: http://www.crummy.com/software/BeautifulSoup/bs4/

[pyup-bot]

Closing this in favor of #226