Fix trove classifier

Author: ben-edna

setup.py

@@ -44,7 +44,7 @@
     },
     classifiers=[
         # Full list: https://pypi.python.org/pypi?%3Aaction=list_classifiers
-        "Development Status :: 3 - Beta",
+        "Development Status :: 4 - Beta",
         "Environment :: Console",
         "Intended Audience :: Developers",
         "License :: OSI Approved :: MIT License",