Attempt to fix travis on Python 3.8 beta (#7492)

JukkaL · web-flow · commit 2bdbacf32a2b · 2019-09-10T16:28:37.000+03:00
diff --git a/test-requirements.txt b/test-requirements.txt
@@ -12,3 +12,4 @@ typing>=3.5.2; python_version < '3.5'
 py>=1.5.2
 virtualenv
 setuptools
+importlib-metadata==0.20
