Update pytest to 4.0.1 (#1359)

This PR updates [pytest](https://pypi.org/project/pytest) from **4.0.0** to **4.0.1**.



<details>
  <summary>Changelog</summary>
  
  
   ### 4.0.1
   ```
   =========================

Bug Fixes
---------

- `3952 &lt;https://github.com/pytest-dev/pytest/issues/3952&gt;`_: Display warnings before &quot;short test summary info&quot; again, but still later warnings in the end.


- `4386 &lt;https://github.com/pytest-dev/pytest/issues/4386&gt;`_: Handle uninitialized exceptioninfo in repr/str.


- `4393 &lt;https://github.com/pytest-dev/pytest/issues/4393&gt;`_: Do not create ``.gitignore``/``README.md`` files in existing cache directories.


- `4400 &lt;https://github.com/pytest-dev/pytest/issues/4400&gt;`_: Rearrange warning handling for the yield test errors so the opt-out in 4.0.x correctly works.


- `4405 &lt;https://github.com/pytest-dev/pytest/issues/4405&gt;`_: Fix collection of testpaths with ``--pyargs``.


- `4412 &lt;https://github.com/pytest-dev/pytest/issues/4412&gt;`_: Fix assertion rewriting involving ``Starred`` + side-effects.


- `4425 &lt;https://github.com/pytest-dev/pytest/issues/4425&gt;`_: Ensure we resolve the absolute path when the given ``--basetemp`` is a relative path.



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

- `4315 &lt;https://github.com/pytest-dev/pytest/issues/4315&gt;`_: Use ``pkg_resources.parse_version`` instead of ``LooseVersion`` in minversion check.


- `4440 &lt;https://github.com/pytest-dev/pytest/issues/4440&gt;`_: Adjust the stack level of some internal pytest warnings.
   ```
   
  
</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

@@ -205,9 +205,9 @@ flake8==3.5.0 \
 mock==2.0.0 \
     --hash=sha256:5ce3c71c5545b472da17b72268978914d0252980348636840bd34a00b5cc96c1 \
     --hash=sha256:b158b6df76edd239b8208d481dc46b6afd45a846b7812ff0ce58971cf5bc8bba
-pytest==4.0.0 \
-    --hash=sha256:c055690dfefa744992f563e8c3a654089a6aa5b8092dded9b6fafbd70b2e45a7 \
-    --hash=sha256:488c842647bbeb350029da10325cb40af0a9c7a2fdda45aeb1dda75b60048ffb
+pytest==4.0.1 \
+    --hash=sha256:ca4761407f1acc85ffd1609f464ca20bb71a767803505bd4127d0e45c5a50e23 \
+    --hash=sha256:1d131cc532be0023ef8ae265e2a779938d0619bb6c2510f52987ffcba7fa1ee4
 coverage==4.5.2 \
     --hash=sha256:06123b58a1410873e22134ca2d88bd36680479fe354955b3579fb8ff150e4d27 \
     --hash=sha256:09e47c529ff77bf042ecfe858fb55c3e3eb97aac2c87f0349ab5a7efd6b3939f \