Add s3cmd package

Add python-dateutil dependency

Add --prefix install options

packages/s3cmd.rb

+require 'package'
+
+class S3cmd < Package
+  description 'Command line tool for managing Amazon S3 and CloudFront services'
+  homepage 'http://s3tools.org/s3cmd'
+  version '2.0.1'
+  source_url 'https://github.com/s3tools/s3cmd/releases/download/v2.0.1/s3cmd-2.0.1.tar.gz'
+  source_sha256 'caf09f1473301c442fba6431c983c361c9af8bde503dac0953f0d2f8f2c53c8f'
+
+  binary_url ({
+  })
+  binary_sha256 ({
+  })
+
+  depends_on 'python27' unless File.exists? "#{CREW_PREFIX}/bin/python"
+
+  def self.install
+    system "python setup.py install --prefix #{CREW_PREFIX} --root #{CREW_DEST_DIR}"
+    system "pip install python-dateutil --prefix #{CREW_PREFIX} --root #{CREW_DEST_DIR}"
+  end
+end