set development status to beta

Author: DenisScherbakov

setup.py

@@ -43,7 +43,7 @@
     long_description = file.read()
 
 CLASSIFIERS = """\
-Development Status :: 3 - Alpha
+Development Status :: 4 - Beta
 Intended Audience :: Science/Research
 Intended Audience :: Developers
 License :: OSI Approved :: Apache Software License