Add py-twine package (#13449)

var/spack/repos/builtin/packages/py-twine/package.py

+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class PyTwine(PythonPackage):
+    """Twine is a utility for publishing Python packages on PyPI."""
+
+    homepage = "https://twine.readthedocs.io/"
+    url      = "https://pypi.io/packages/source/t/twine/twine-2.0.0.tar.gz"
+
+    version('2.0.0', sha256='9fe7091715c7576df166df8ef6654e61bada39571783f2fd415bdcba867c6993')
+
+    depends_on('python@3.6:', type=('build', 'run'))
+    depends_on('py-pkginfo@1.4.2:', type=('build', 'run'))
+    depends_on('py-readme-renderer@21.0:', type=('build', 'run'))
+    depends_on('py-requests-toolbelt@0.8.0:0.8.999,0.9.1:', type=('build', 'run'))
+    depends_on('py-setuptools@0.7.0:', type=('build', 'run'))
+    depends_on('py-tqdm@4.14:', type=('build', 'run'))