added pyproject.toml to specify build dependencies & build backend

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- added `pyproject.toml` to specify build dependencies & build backend
+
 ### Removed
 - compatibility with `python3.5`
 

pyproject.toml

@@ -0,0 +1,4 @@
+# https://setuptools.readthedocs.io/en/latest/build_meta.html
+[build-system]
+requires = ["setuptools", "wheel", "setuptools_scm"]
+build-backend = "setuptools.build_meta"