Bump pytest from 3.7.1 to 3.7.2

Bumps [pytest](https://github.com/pytest-dev/pytest) from 3.7.1 to 3.7.2.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@3.7.1...3.7.2)

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

Author: dependabot-support

dev-requirements.txt

@@ -5,7 +5,7 @@ invoke==1.1.1
 Flask==1.0.2
 
 # Testing
-pytest==3.7.1
+pytest==3.7.2
 tox==3.2.1
 faker==0.9.0