Make pep 517 compat

pyproject.toml

@@ -1,17 +1,3 @@
-[tool.black]
-exclude = '''
-(
-  /(
-      \.eggs
-    | \.git
-    | \.hg
-    | \.mypy_cache
-    | \.tox
-    | \.venv
-    | _build
-    | build
-    | dist
-  )/
-)
-'''
-target_version = ['py38']
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"