Add jam package

packages/jam.rb

+require 'package'
+
+class Jam < Package
+  description 'Jam is a software build tool that makes building simple things simple and building complicated things manageable.'
+  homepage 'https://www.perforce.com/documentation/jam-documentation'
+  version '2.6'
+  source_url 'https://swarm.workshop.perforce.com/downloads/guest/perforce_software/jam/jam-2.6.zip'
+  source_sha256 '7c510be24dc9d0912886c4364dc17a013e042408386f6b937e30bd9928d5223c'
+
+  binary_url ({
+  })
+  binary_sha256 ({
+  })
+
+  depends_on 'unzip' => :build
+
+  def self.build
+    system "sed -i 's,jam0,jam,g' Makefile"
+    system "make"
+  end
+
+  def self.install
+    system "install -Dm755 jam #{CREW_DEST_PREFIX}/bin/jam"
+  end
+end