added project classifiers

setup.py

@@ -33,4 +33,15 @@ setup(
         ]
     },
     include_package_data=True,
+    classifiers=[
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'License :: OSI Approved :: MIT License',
+        'Operating System :: OS Independent',
+        'Development Status :: 5 - Production/Stable'
+    ],
+    python_requires='>=3.6'
 )