Switch to setuptools-scm for versioning

Following other pytest projects like pytest-html,
that use setuptool-scm to manage version, it would
be nice other projects follow the suit and
let setuptools-scm manage version of this project.

.gitignore

@@ -57,4 +57,7 @@ docs/_build/
 target/
 
 .venv*
-.idea
+.idea
+
+# generated by setuptools_scm
+pytest_asyncio/_version.py

pytest_asyncio/__init__.py

@@ -1,2 +1,4 @@
+
 """The main point for importing pytest-asyncio items."""
-__version__ = "0.10.0.dev0"
+
+from ._version import version as __version__

setup.py

@@ -21,7 +21,8 @@ def find_version():
 
 setup(
     name="pytest-asyncio",
-    version=find_version(),
+    use_scm_version={"write_to": "pytest_asyncio/_version.py"},
+    setup_requires=["setuptools-scm"],
     packages=find_packages(),
     url="https://github.com/pytest-dev/pytest-asyncio",
     license="Apache 2.0",