Update pytest to 3.0.0

[pyup-bot]

There's a new version of pytest available.
You are currently using 2.9.2. I have updated it to 3.0.0

Changelog

2.9.3.dev

Bug Fixes

• Improve error message with fixture lookup errors: add an 'E' to the first
  line and '>' to the rest. Fixes 717. Thanks blueyed for reporting and
  a PR, eolo999_ for the initial PR and tomviner_ for his guidance during
  EuroPython2016 sprint.
• Text documents without any doctests no longer appear as "skipped".
  Thanks graingert_ for reporting and providing a full PR (1580_).
• Fix internal error issue when method argument is missing for
  teardown_method(). Fixes (1605_).
• Fix exception visualization in case the current working directory (CWD) gets
  deleted during testing. Fixes (1235). Thanks bukzor_ for reporting. PR by
  marscher. Thanks nicoddemus_ for his help.
• Ensure that a module within a namespace package can be found when it
  is specified on the command line together with the --pyargs
  option. Thanks to taschini_ for the PR (1597_).
• Raise helpful failure message, when requesting parametrized fixture at runtime,
  e.g. with request.getfuncargvalue. BACKWARD INCOMPAT: Previously these params
  were simply never defined. So a fixture decorated like pytest.fixture(params=[0, 1, 2])
  only ran once. Now a failure is raised. Fixes (460). Thanks to
  nikratio for bug report, RedBeardCode_ and tomviner_ for the PR.
• Create correct diff for strings ending with newlines. Fixes (1553).
  Thanks Vogtinator for reporting. Thanks to RedBeardCode_ and
  tomviner_ for PR.
• Rename getfuncargvalue to getfixturevalue. getfuncargvalue is
  deprecated but still present. Thanks to RedBeardCode_ and tomviner_
  for PR (1626_).
• Refined logic for determining the rootdir, considering only valid
  paths which fixes a number of issues: 1594, 1435 and 1471.
  Thanks to blueyed and davehunt_ for the PR.
• Always include full assertion explanation. The previous behaviour was hiding
  sub-expressions that happened to be False, assuming this was redundant information.
  Thanks bagerard_ for reporting (1503). Thanks to davehunt and
  tomviner_ for PR.
• Renamed the pytest pdb module (plugin) into debugging.
• Improve of the test output for logical expression with brackets.
  Fixes(925). Thanks DRMacIver for reporting. Thanks to RedBeardCode_
  for PR.
• Updated docstrings with a more uniform style.
• Add stderr write for pytest.exit(msg) during startup. Previously the message was never shown.
  Thanks BeyondEvil_ for reporting 1210. Thanks to JonathonSonesen and
  tomviner_ for PR.
• ImportErrors in plugins now are a fatal error instead of issuing a
  pytest warning (1479). Thanks to The-Compiler for the PR.
• Fixed collection of classes with custom __new__ method.
  Fixes 1579. Thanks to Stranger6667 for the PR.
• Fixed scope overriding inside metafunc.parametrize (634).
  Thanks to Stranger6667 for the PR.
• Fixed the total tests tally in junit xml output (1798).
  Thanks to cryporchild for the PR.
• pytest_terminal_summary hook now receives the exitstatus
  of the test session as argument. Thanks blueyed_ for the PR (1809_).

• Fixed off-by-one error with lines from request.node.warn.
  Thanks to blueyed_ for the PR.

Changes

• Change report.outcome for xpassed tests to "passed" in non-strict
  mode and "failed" in strict mode. Thanks to hackebrot_ for the PR
  (1795) and gprasad84 for report (1546_).
• Tests marked with xfail(strict=False) (the default) now appear in
  JUnitXML reports as passing tests instead of skipped.
  Thanks to hackebrot_ for the PR (1795_).

.. _1795: pytest-dev/pytest#1795
.. _1546: pytest-dev/pytest#1546
.. _gprasad84: https://github.com/gprasad84

.. _1210: pytest-dev/pytest#1210
.. _1435: pytest-dev/pytest#1435
.. _1471: pytest-dev/pytest#1471
.. _1479: pytest-dev/pytest#1479
.. _1503: pytest-dev/pytest#1503
.. _1553: pytest-dev/pytest#1553
.. _1579: pytest-dev/pytest#1579
.. _1580: pytest-dev/pytest#1580
.. _1594: pytest-dev/pytest#1594
.. _1597: pytest-dev/pytest#1597
.. _1605: pytest-dev/pytest#1605
.. _1626: pytest-dev/pytest#1626
.. _1798: pytest-dev/pytest#1798
.. _1809: pytest-dev/pytest#1809
.. _460: pytest-dev/pytest#460
.. _634: pytest-dev/pytest#634
.. _717: pytest-dev/pytest#717
.. _925: pytest-dev/pytest#925

.. _bagerard: https://github.com/bagerard
.. _BeyondEvil: https://github.com/BeyondEvil
.. _blueyed: https://github.com/blueyed
.. _cryporchild: https://github.com/cryporchild
.. _davehunt: https://github.com/davehunt
.. _DRMacIver: https://github.com/DRMacIver
.. _eolo999: https://github.com/eolo999
.. _graingert: https://github.com/graingert
.. _JonathonSonesen: https://github.com/JonathonSonesen
.. _nikratio: https://github.com/nikratio
.. _RedBeardCode: https://github.com/RedBeardCode
.. _Stranger6667: https://github.com/Stranger6667
.. _taschini: https://github.com/taschini
.. _Vogtinator: https://github.com/Vogtinator

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[pyup-bot]

Closing this in favor of #136