cowsay: new package (#11743)

- A program that generates ASCII pictures of a cow with a message.

- This is used by the ISC19 Singularity tutorial, so we should probably
  have it in Spack.

var/spack/repos/builtin/packages/cowsay/package.py

@@ -0,0 +1,21 @@
+# 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 Cowsay(Package):
+    """A program that generates ASCII pictures of a cow with a message."""
+
+    homepage = "https://github.com/tnalpgge/rank-amateur-cowsay"
+    url      = "https://github.com/tnalpgge/rank-amateur-cowsay/archive/cowsay-3.04.tar.gz"
+
+    version('3.04', sha256='d8b871332cfc1f0b6c16832ecca413ca0ac14d58626491a6733829e3d655878b')
+
+    depends_on('perl', type=('run'))
+
+    def install(self, spec, prefix):
+        install_sh = Executable('./install.sh')
+        install_sh(prefix)