allow pytest 6

diff --git a/pyproject.toml b/pyproject.toml
index 51d8b8e86a1c7dc8c13fd176f5ec96ec41925aef..92bbb54984149e791ac484c869f77d16e0555e54 100644 (file)
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,7 +20,7 @@ sniffio = {version="^1.1", optional=true}
 
 [tool.poetry.dev-dependencies]
 mypy = "^0.782"
-pytest = "^5.4.1"
+pytest = ">=5.4.1,<7"
 pytest-cov = "^2.10.0"
 flake8 = "^3.7.9"
 sphinx = "^3.0.0"