Bump pytest from 4.3.1 to 4.5.0

Bumps [pytest](https://github.com/pytest-dev/pytest) from 4.3.1 to 4.5.0.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@4.3.1...4.5.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

requirements.txt

@@ -26,7 +26,7 @@ pycparser==2.19
 pyflakes==2.1.1
 Pygments==2.3.1
 pyparsing==2.3.0
-pytest==4.3.1
+pytest==4.5.0
 pytest-cache==1.0
 pytest-cov==2.7.1
 pytest-flakes==4.0.0