build(deps): bump pytest from 5.4.3 to 6.0.1

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.4.3 to 6.0.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@5.4.3...6.0.1)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

travis/requirements.txt

@@ -1,7 +1,7 @@
 coverage==5.2.1
 freezegun==0.3.15
 pylint==2.6.0
-pytest==5.4.3
+pytest==6.0.1
 pytest-asyncio==0.14.0
 pytest-cov==2.10.1
 pytest-random-order==1.0.4