Merge pull request #80 from Tivoli/master

Add support for iojs 2.1.0

packages/iojs.rb

+require 'package'
+
+class Iojs < Package
+  version '2.2.1'
+  source_url 'https://iojs.org/dist/v2.2.1/iojs-v2.2.1.tar.gz'
+  source_sha1 '2b4a43cc1333526cbc5ac2e30d765a4d9c26427c'
+
+  depends_on 'buildessential'
+
+  def self.build
+    system "./configure"
+    system "make"
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end