fix: test failures around missing 'event_loop' fixture

Caused by the recent pytest-asyncio 1.0 release, which included pytest-dev/pytest-asyncio#1106.

This is probably not the best fix - but it unbreaks things for now.

Author: bhearsum

setup.py

@@ -25,7 +25,8 @@
     "flake8",
     "flake8_docstrings",
     "mock",
-    "pytest",
+    # doesn't support python 3.8
+    "pytest<1.0",
     "pytest-asyncio",
     "pytest-cov",
     "pytest-mock",

tox.ini

@@ -23,7 +23,7 @@ deps =
     flake8_docstrings
     mock
     pytest
-    pytest-asyncio
+    pytest-asyncio<1.0
     pytest-mock
     pytest-random-order
     virtualenv