Add pyproject.toml per PEP 518 for use by a future pip release. Ref #581.

jaraco · jaraco · commit 336a065df01a · 2017-01-17T09:44:37.000-05:00
diff --git a/pyproject.toml b/pyproject.toml
@@ -0,0 +1,9 @@
+[build-system]
+# for Setuptools, its own requirements are build requirements,
+# so keep this in sync with install_requires in setup.py.
+requires = [
+    "wheel",
+    "packaging>=16.8",
+    "six>=1.10.0",
+    "appdirs>=1.4.0",
+]
