Use python-magic-bin on windows

setup.py

@@ -34,7 +34,8 @@ setup(name='Mastodon.py',
           'requests>=2.4.2', 
           'python-dateutil', 
           'six',
-          'python-magic',
+          'python-magic-bin ; platform_system=="Windows"',
+          'python-magic ; platform_system!="Windows"',
           'decorator>=4.0.0', 
       ] + blurhash_deps,
       tests_require=test_deps,