Add pmd package

packages/pmd.rb

+require 'package'
+
+class Pmd < Package
+  description 'An extensible cross-language static code analyzer.'
+  homepage 'https://pmd.github.io/'
+  version '5.8.1'
+  source_url 'https://github.com/pmd/pmd/releases/download/pmd_releases%2F5.8.1/pmd-bin-5.8.1.zip'
+  source_sha256 '2d854e30717b66e253213f36d4bcd202b83b180ea427836797d13a857c19a6b4'
+
+  binary_url ({
+  })
+  binary_sha256 ({
+  })
+
+  depends_on 'unzip'
+
+  def self.install
+    system "mkdir -p #{CREW_DEST_PREFIX}/bin"
+    system "mkdir -p #{CREW_DEST_LIB_PREFIX}/pmd"
+    system "cp -r . #{CREW_DEST_LIB_PREFIX}/pmd"
+    FileUtils.cd("#{CREW_DEST_PREFIX}/bin") do
+      system "ln -s #{CREW_LIB_PREFIX}/pmd/bin/run.sh pmd"
+    end
+  end
+end