Merge pull request #1147 from uberhacker/add-units-package

Add units package

packages/units.rb

+require 'package'
+
+class Units < Package
+  description 'GNU Units converts quantities expressed in various systems of measurement to their equivalents in other systems of measurement.'
+  homepage 'https://www.gnu.org/software/units/units.html'
+  version '2.14'
+  source_url 'https://ftp.gnu.org/gnu/units/units-2.14.tar.gz'
+  source_sha256 '9d33893d82f3ddd831d5822992007c40bcd0826ae67d3cbc96539951fb0a82e8'
+
+  def self.build
+    system './configure'
+    system 'make'
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end