added stunnel package

packages/stunnel.rb

@@ -0,0 +1,18 @@
+require 'package'
+
+class Stunnel < Package
+  version '5.41'
+  source_url 'https://www.stunnel.org/downloads/stunnel-5.41.tar.gz'
+  source_sha1 '9aa8335e0f9571480b0d62b4b58d9d510447b732'
+
+  depends_on 'openssl'
+
+  def self.build
+    system "./configure"
+    system "make"
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end