Update classifier to Development Status :: 4 - Beta (#291)

Bump the stability from https://pypi.org/classifiers/

Signed-off-by: Serge Smertin <[email protected]>

Author: nfx

setup.py

@@ -25,7 +25,7 @@
       url="https://databricks-sdk-py.readthedocs.io",
       keywords="databricks sdk",
       classifiers=[
-          "Development Status :: 3 - Alpha",
+          "Development Status :: 4 - Beta",
           "Intended Audience :: Developers",
           "Intended Audience :: Science/Research",
           "Intended Audience :: System Administrators",