feat: expose library version at googleapiclient.__version__ (#1623)

Co-authored-by: Anthonios Partheniou <partheniou@google.com>
diff --git a/setup.py b/setup.py
index ed8fa9b..a311f16 100644
--- a/setup.py
+++ b/setup.py
@@ -51,7 +51,12 @@
 with io.open(readme_filename, encoding="utf-8") as readme_file:
     readme = readme_file.read()
 
-version = "2.33.0"
+package_root = os.path.abspath(os.path.dirname(__file__))
+
+version = {}
+with open(os.path.join(package_root, "googleapiclient/version.py")) as fp:
+    exec(fp.read(), version)
+version = version["__version__"]
 
 setup(
     name="google-api-python-client",