Add py-crcmod (#19207)

* Add py-crcmod

* Updating homepage

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

@@ -0,0 +1,25 @@
+# Copyright 2013-2020 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 PyCrcmod(PythonPackage):
+    """Python module for generating objects that
+       compute the Cyclic Redundancy Check (CRC)"""
+
+    homepage = "http://crcmod.sourceforge.net/"
+    url      = "https://pypi.io/packages/source/c/crcmod/crcmod-1.7.tar.gz"
+
+    version('1.7', sha256='dc7051a0db5f2bd48665a990d3ec1cc305a466a77358ca4492826f41f283601e')
+    version('1.6', sha256='56d27d035ea029c6ed96779ca042c0136d39d106e3c30baa6422738c7d86aaa5')
+
+    depends_on('python@2.4:2.7,3.1:', type=('build', 'run'))
+    depends_on('py-setuptools@40.0.0:', type='build')
+
+    def install(self, spec, prefix):
+        # Override install to avoid
+        #   error: option --single-version-externally-managed not recognized
+        setup_py('install', '--root=/', '--prefix={0}'.format(prefix))