Rely on setuptools_scm 3.4 and setuptools 42. Now setup.py is optiona…

…l. Remove setuptools from test environment.

pyproject.toml

@@ -1,6 +1,8 @@
 [build-system]
-requires = ["setuptools>=34.4", "wheel", "setuptools_scm>=1.15"]
+requires = ["setuptools>=42", "wheel", "setuptools_scm>=3.4"]
 build-backend = "setuptools.build_meta"
 
 [tool.black]
 skip-string-normalization = true
+
+[tool.setuptools_scm]

setup.cfg

@@ -20,7 +20,7 @@ packages = find:
 include_package_data = true
 python_requires = >=3.6
 install_requires =
-setup_requires = setuptools_scm >= 1.15.0
+setup_requires = setuptools_scm >= 3.4
 
 [options.extras_require]
 testing =

setup.py

@@ -3,4 +3,4 @@
 import setuptools
 
 if __name__ == "__main__":
-    setuptools.setup(use_scm_version=True)
+    setuptools.setup()

tox.ini

@@ -11,7 +11,6 @@ requires =
 
 [testenv]
 deps =
-	setuptools>=31.0.1
 pip_version = pip
 commands =
 	pytest {posargs}