Update pytest to 3.10.0 (#1292)

This PR updates [pytest](https://pypi.org/project/pytest) from **3.9.3** to **3.10.0**.



<details>
  <summary>Changelog</summary>
  
  
   ### 3.10.0
   ```
   ==========================

Features
--------

- `2619 &lt;https://github.com/pytest-dev/pytest/issues/2619&gt;`_: Resume capturing output after ``continue`` with ``__import__(&quot;pdb&quot;).set_trace()``.

  This also adds a new ``pytest_leave_pdb`` hook, and passes in ``pdb`` to the
  existing ``pytest_enter_pdb`` hook.


- `4147 &lt;https://github.com/pytest-dev/pytest/issues/4147&gt;`_: Add ``-sw``, ``--stepwise`` as an alternative to ``--lf -x`` for stopping at the first failure, but starting the next test invocation from that test.  See `the documentation &lt;https://docs.pytest.org/en/latest/cache.htmlstepwise&gt;`__ for more info.


- `4188 &lt;https://github.com/pytest-dev/pytest/issues/4188&gt;`_: Make ``--color`` emit colorful dots when not running in verbose mode. Earlier, it would only colorize the test-by-test output if ``--verbose`` was also passed.


- `4225 &lt;https://github.com/pytest-dev/pytest/issues/4225&gt;`_: Improve performance with collection reporting in non-quiet mode with terminals.

  The &quot;collecting …&quot; message is only printed/updated every 0.5s.



Bug Fixes
---------

- `2701 &lt;https://github.com/pytest-dev/pytest/issues/2701&gt;`_: Fix false ``RemovedInPytest4Warning: usage of Session... is deprecated, please use pytest`` warnings.


- `4046 &lt;https://github.com/pytest-dev/pytest/issues/4046&gt;`_: Fix problems with running tests in package ``__init__.py`` files.


- `4260 &lt;https://github.com/pytest-dev/pytest/issues/4260&gt;`_: Swallow warnings during anonymous compilation of source.


- `4262 &lt;https://github.com/pytest-dev/pytest/issues/4262&gt;`_: Fix access denied error when deleting stale directories created by ``tmpdir`` / ``tmp_path``.


- `611 &lt;https://github.com/pytest-dev/pytest/issues/611&gt;`_: Naming a fixture ``request`` will now raise a warning: the ``request`` fixture is internal and
  should not be overwritten as it will lead to internal errors.



Improved Documentation
----------------------

- `4255 &lt;https://github.com/pytest-dev/pytest/issues/4255&gt;`_: Added missing documentation about the fact that module names passed to filter warnings are not regex-escaped.



Trivial/Internal Changes
------------------------

- `4272 &lt;https://github.com/pytest-dev/pytest/issues/4272&gt;`_: Display cachedir also in non-verbose mode if non-default.


- `4277 &lt;https://github.com/pytest-dev/pytest/issues/4277&gt;`_: pdb: improve message about output capturing with ``set_trace``.

  Do not display &quot;IO-capturing turned off/on&quot; when ``-s`` is used to avoid
  confusion.


- `4279 &lt;https://github.com/pytest-dev/pytest/issues/4279&gt;`_: Improve message and stack level of warnings issued by ``monkeypatch.setenv`` when the value of the environment variable is not a ``str``.
   ```
   
  
</details>


 

<details>
  <summary>Links</summary>
  
  - PyPI: https://pypi.org/project/pytest
  - Changelog: https://pyup.io/changelogs/pytest/
  - Homepage: https://docs.pytest.org/en/latest/
</details>

requirements.txt

@@ -206,9 +206,9 @@ flake8==3.5.0 \
 mock==2.0.0 \
     --hash=sha256:5ce3c71c5545b472da17b72268978914d0252980348636840bd34a00b5cc96c1 \
     --hash=sha256:b158b6df76edd239b8208d481dc46b6afd45a846b7812ff0ce58971cf5bc8bba
-pytest==3.9.3 \
-    --hash=sha256:bf47e8ed20d03764f963f0070ff1c8fda6e2671fc5dd562a4d3b7148ad60f5ca \
-    --hash=sha256:a9e5e8d7ab9d5b0747f37740276eb362e6a76275d76cebbb52c6049d93b475db
+pytest==3.10.0 \
+    --hash=sha256:630ff1dbe04f469ee78faa5660f712e58b953da7df22ea5d828c9012e134da43 \
+    --hash=sha256:a2b5232735dd0b736cbea9c0f09e5070d78fcaba2823a4f6f09d9a81bd19415c
 coverage==4.5.1 \
     --hash=sha256:7608a3dd5d73cb06c531b8925e0ef8d3de31fed2544a7de6c63960a1e73ea4bc \
     --hash=sha256:3a2184c6d797a125dca8367878d3b9a178b6fdd05fdc2d35d758c3006a1cd694 \