Minor housekeeping (#993)

* Use the standard pyproject.toml build-system
* Update publish-sdist with  python3.9
* Set min python version to 3.7

.github/workflows/publish-sdist.yml

@@ -11,10 +11,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@master
-      - name: Set up Python 3.6
+      - name: Set up Python 3.9
         uses: actions/setup-python@v2
         with:
-          python-version: 3.6
+          python-version: 3.9
       - name: Build a source tarball
         run:
             python setup.py sdist

pyproject.toml

@@ -1,2 +1,6 @@
 [build-system]
-requires = ["setuptools", "wheel"]
+requires = [
+    "setuptools>=42",
+    "wheel",
+]
+build-backend = "setuptools.build_meta"

setup.py

@@ -57,15 +57,16 @@
         'docs': ['sphinx', 'sphinx-bluebrain-theme', 'sphinx-autorun'],
     },
     include_package_data=True,
-    python_requires='>=3.5',
+    python_requires='>=3.7',
     classifiers=[
         'Development Status :: 6 - Mature',
         'Intended Audience :: Education',
         'Intended Audience :: Science/Research',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
         'Topic :: Scientific/Engineering :: Bio-Informatics',
     ],
     use_scm_version={"local_scheme": "no-local-version"},