Add gradle package

packages/gradle.rb

+require 'package'
+
+class Gradle < Package
+  description 'From mobile apps to microservices, from small startups to big enterprises, Gradle helps teams build, automate and deliver better software, faster.'
+  homepage 'https://gradle.org/'
+  version '4.4.1'
+  source_url 'https://services.gradle.org/distributions/gradle-4.4.1-bin.zip'
+  source_sha256 'e7cf7d1853dfc30c1c44f571d3919eeeedef002823b66b6a988d27e919686389'
+
+  binary_url ({
+  })
+  binary_sha256 ({
+  })
+
+  depends_on 'unzip' => :build
+  depends_on 'jdk8'
+
+  def self.install
+    system "mkdir -p #{CREW_DEST_PREFIX}/bin"
+    system "mkdir -p #{CREW_DEST_PREFIX}/share/gradle"
+    system "cp -r . #{CREW_DEST_PREFIX}/share/gradle"
+    system "ln -s #{CREW_PREFIX}/share/gradle/bin/gradle #{CREW_DEST_PREFIX}/bin"
+  end
+end