Use get_metadata_version in upload_file

Previously this value was hard-coded to '1.0', which was inaccurate for
many packages.

Fixes pypa#1381

setuptools/command/upload.py

@@ -84,7 +84,7 @@ def upload_file(self, command, pyversion, filename):
             'md5_digest': hashlib.md5(content).hexdigest(),
 
             # additional meta-data
-            'metadata_version': '1.0',
+            'metadata_version': str(meta.get_metadata_version()),
             'summary': meta.get_description(),
             'home_page': meta.get_url(),
             'author': meta.get_contact(),

setuptools/tests/test_upload.py

@@ -33,7 +33,6 @@ def _parse_upload_body(body):
 
 
 class TestUploadTest:
-    @pytest.mark.xfail(reason='Issue #1381')
     @mock.patch('setuptools.command.upload.urlopen')
     def test_upload_metadata(self, patch, tmpdir):
         dist = Distribution()