Add pytest_django.__version__

This can avoid import importlib-metadata or pkg_resources etc.
Similar to pytest.

Author: bluetech

.gitignore

@@ -16,3 +16,5 @@ _build
 .Python
 .eggs
 *.egg
+# autogenerated by setuptools-scm
+/pytest_django/_version.py

pytest_django/__init__.py

@@ -0,0 +1,10 @@
+try:
+    from ._version import version as __version__
+except ImportError:  # pragma: no cover
+    # Broken installation, we don't even try.
+    __version__ = "unknown"
+
+
+__all__ = (
+    "__version__",
+)

setup.py

@@ -1,5 +1,7 @@
 from setuptools import setup
 
 setup(
-    use_scm_version=True,
+    use_scm_version={
+        'write_to': 'pytest_django/_version.py',
+    },
 )