Fix python_requires

Author: pganssle

setup.cfg

@@ -21,10 +21,10 @@ classifiers =
 project_urls =
     Bug Reports = https://github.com/python/tzdata/issues
     Source = https://github.com/python/tzdata
-python_requires = *.*  # This is a data-only package
 
 [options]
 packages = tzdata
+python_requires = >=2
 include_package_data = True
 package_dir =
     =src