[tests] Remove old coverage required version

Bastien Vallet · Djailla · commit f0a9c6b4ded6 · 2019-10-27T19:56:48.000+01:00
diff --git a/requirements_test.txt b/requirements_test.txt
@@ -1,4 +1,4 @@
 aiohttp
-coverage>=4.0,<4.4  # TODO: https://github.com/benoitc/gunicorn/issues/1548
+coverage
 pytest
-pytest-cov==2.5.1
+pytest-cov
