Replace deprecated `allows-prereleases` with `allow-prereleases`
@@ -52,7 +52,7 @@ factory-boy = "=2.12.0"
mypy = "^0.750"
pdbpp = "^0.10.2"
flake8 = "^3.7"
-black = {version = "^19.10b0",allows-prereleases = true}
+black = {version = "^19.10b0",allow-prereleases = true}
[build-system]
requires = ["poetry>=0.12"]
