Added a very basic Namespace class.

lib/oga/xml/namespace.rb

@@ -0,0 +1,29 @@
+module Oga
+  module XML
+    ##
+    # The Namespace class contains information about XML namespaces such as the
+    # name and URI.
+    #
+    class Namespace
+      attr_accessor :name, :uri
+
+      ##
+      # @param [Hash] options
+      #
+      # @option options [String] :name
+      # @option options [String] :uri
+      #
+      def initialize(options = {})
+        @name = options[:name]
+        @uri  = options[:uri]
+      end
+
+      ##
+      # @return [String]
+      #
+      def to_s
+        return name.to_s
+      end
+    end # Namespace
+  end # XML
+end # Oga