Update Vendored Erubis to 2.6.6

vendor/plugins/erubis/test/data/users-guide/def_method.rb

@@ -0,0 +1,14 @@
+require 'erubis'
+s = "hello <%= name %>"
+eruby = Erubis::Eruby.new(s)
+filename = 'hello.rhtml'
+
+## define instance method to Dummy class (or module)
+class Dummy; end
+eruby.def_method(Dummy, 'render(name)', filename)  # filename is optional
+p Dummy.new.render('world')    #=> "hello world"
+
+## define singleton method to dummy object
+obj = Object.new
+eruby.def_method(obj, 'render(name)', filename)    # filename is optional
+p obj.render('world')          #=> "hello world"