Create pyproject.toml

This adds configuration for Black code formatter

Author: Anand Sanmukhani

pyproject.toml

@@ -0,0 +1,22 @@
+[tool.black]
+line-length = 100
+target_version = ['py37']
+include = '\.pyi?$'
+exclude = '''
+
+(
+  /(
+      \.eggs         # exclude a few common directories in the
+    | \.git          # root of the project
+    | \.hg
+    | \.mypy_cache
+    | \.tox
+    | \.venv
+    | _build
+    | buck-out
+    | build
+    | dist
+    | docs
+  )/
+)
+'''