Update coverage to 5.5

[pyup-bot]

This PR updates coverage from 5.4 to 5.5.

Changelog

5.5

--------------------------

- ``coverage combine`` has a new option, ``--keep`` to keep the original data
files after combining them.  The default is still to delete the files after
they have been combined.  This was requested in `issue 1108`_ and implemented
in `pull request 1110`_.  Thanks, Éric Larivière.

- When reporting missing branches in ``coverage report``, branches aren't
reported that jump to missing lines.  This adds to the long-standing behavior
of not reporting branches from missing lines.  Now branches are only reported
if both the source and destination lines are executed.  Closes both `issue
1065`_ and `issue 955`_.

- Minor improvements to the HTML report:

- The state of the line visibility selector buttons is saved in local storage
 so you don't have to fiddle with them so often, fixing `issue 1123`_.

- It has a little more room for line numbers so that 4-digit numbers work
 well, fixing `issue 1124`_.

- Improved the error message when combining line and branch data, so that users
will be more likely to understand what's happening, closing `issue 803`_.

.. _issue 803: https://github.com/nedbat/coveragepy/issues/803
.. _issue 955: https://github.com/nedbat/coveragepy/issues/955
.. _issue 1065: https://github.com/nedbat/coveragepy/issues/1065
.. _issue 1108: https://github.com/nedbat/coveragepy/issues/1108
.. _pull request 1110: https://github.com/nedbat/coveragepy/pull/1110
.. _issue 1123: https://github.com/nedbat/coveragepy/issues/1123
.. _issue 1124: https://github.com/nedbat/coveragepy/issues/1124


.. _changes_54:

Links

• PyPI: https://pypi.org/project/coverage
• Changelog: https://pyup.io/changelogs/coverage/
• Repo: https://github.com/nedbat/coveragepy

[pyup-bot]

Closing this in favor of #155