Require attrs >= 18.1.0 to work around ctypes failure in Vim

Fixes #116, #539

Pipfile

@@ -5,7 +5,7 @@ name = "pypi"
 
 [packages]
 aiohttp = ">=3.3.2"
-attrs = ">=17.4.0"
+attrs = ">=18.1.0"
 click = ">=6.5"
 appdirs = "*"
 toml = ">=0.9.4"

pyproject.toml

@@ -69,7 +69,7 @@ black = "black:main"
 
 [tool.poetry.dependencies]
 python = "^3.6"
-attrs = "^17.4"
+attrs = "^18.1"
 click = "^6.5"
 toml = "^0.9.4"
 appdirs = "^1.4"

setup.py

@@ -41,7 +41,7 @@ def get_version() -> str:
     package_data={"blib2to3": ["*.txt"]},
     python_requires=">=3.6",
     zip_safe=False,
-    install_requires=["click>=6.5", "attrs>=17.4.0", "appdirs", "toml>=0.9.4"],
+    install_requires=["click>=6.5", "attrs>=18.1.0", "appdirs", "toml>=0.9.4"],
     extras_require={"d": ["aiohttp>=3.3.2"]},
     test_suite="tests.test_black",
     classifiers=[