Add c_ares package

packages/c_ares.rb

+require 'package'
+
+class C_ares < Package
+  description 'c-ares is a C library for asynchronous DNS requests (including name resolves).'
+  homepage 'https://c-ares.haxx.se/'
+  version '1.13.0'
+  source_url 'https://c-ares.haxx.se/download/c-ares-1.13.0.tar.gz'
+  source_sha1 'dde50284cc3d505fb2463ff6276e61d5531b1d68'
+
+  def self.build
+    system "./configure"
+    system "make"
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end