Converted to PyPy package

pyproject.toml

@@ -0,0 +1,20 @@
+[build-system]
+requires = ["setuptools>=42", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[tool.black]
+line-length = 100
+target-version = ['py38']
+include = '\.pyi?$'
+
+[tool.isort]
+profile = "black"
+multi_line_output = 3
+line_length = 100
+
+[tool.mypy]
+python_version = "3.8"
+warn_return_any = true
+warn_unused_configs = true
+disallow_untyped_defs = true
+disallow_incomplete_defs = true