Update Vendored Erubis to 2.6.6

vendor/plugins/erubis/test/data/users-guide/example1.rb

@@ -0,0 +1,17 @@
+require 'erubis'
+input = File.read('example1.eruby')
+eruby = Erubis::Eruby.new(input)    # create Eruby object
+
+puts "---------- script source ---"
+puts eruby.src                      # print script source
+
+puts "---------- result ----------"
+list = ['aaa', 'bbb', 'ccc']
+puts eruby.result(binding())        # get result
+## or puts eruby.result(:list=>list)  # or pass Hash instead of Binding
+
+## # or
+## eruby = Erubis::Eruby.new
+## input = File.read('example1.eruby')
+## src = eruby.convert(input)
+## eval src