add new package : busybox@1.31.1 (#13871)

* add new package : busybox@1.31.1

* 1. add some other version for busybox
2. change Busybox class to MakefilePackage
3. move make('defconfig') and make() to build() function
4. change install_tree('', prefix) to install_tree('.', prefix)

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

@@ -0,0 +1,28 @@
+# 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 Busybox(MakefilePackage):
+    """BusyBox combines tiny versions of many common UNIX utilities into
+    a single small executable. It provides replacements for most of
+    the utilities you usually find in GNU fileutils, shellutils, etc"""
+
+    homepage = "https://busybox.net"
+    url      = "https://busybox.net/downloads/busybox-1.31.0.tar.bz2"
+
+    version('1.31.1', sha256='d0f940a72f648943c1f2211e0e3117387c31d765137d92bd8284a3fb9752a998')
+    version('1.31.0', sha256='0e4925392fd9f3743cc517e031b68b012b24a63b0cf6c1ff03cce7bb3846cc99')
+    version('1.30.1', sha256='3d1d04a4dbd34048f4794815a5c48ebb9eb53c5277e09ffffc060323b95dfbdc')
+    version('1.30.0', sha256='9553da068c0a30b1b8b72479908c1ba58672e2be7b535363a88de5e0f7bc04ce')
+
+    def build(self, spec, prefix):
+        make('defconfig')
+        make()
+
+    def install(self, spec, prefix):
+        make('install')
+        install_tree('.', prefix)