chore(dependencies): Update pytest-cov to 2.6.1

[pyup-bot]

This PR updates pytest-cov from 2.6.0 to 2.6.1.

Changelog

2.6.1

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

* Added support for Pytest 4.1. Contributed by Daniel Hahler and Семён Марьясин in
`253 <https://github.com/pytest-dev/pytest-cov/pull/253>`_ and
`230 <https://github.com/pytest-dev/pytest-cov/pull/230>`_.
* Various test and docs fixes. Contributed by Daniel Hahler in
`224 <https://github.com/pytest-dev/pytest-cov/pull/224>`_ and
`223 <https://github.com/pytest-dev/pytest-cov/pull/223>`_.
* Fixed the "Module already imported" issue (`211 <https://github.com/pytest-dev/pytest-cov/issues/211>`_).
Contributed by Daniel Hahler in `228 <https://github.com/pytest-dev/pytest-cov/pull/228>`_.

Links

• PyPI: https://pypi.org/project/pytest-cov
• Changelog: https://pyup.io/changelogs/pytest-cov/
• Repo: https://github.com/pytest-dev/pytest-cov