require readline only when using an interactive shell

bin/therubyracer

@@ -2,7 +2,6 @@
 lib = File.expand_path(File.dirname(__FILE__) + '/../lib')
 $:.unshift(lib) if File.exists?(lib) unless $:.member?(lib)
 
-require 'readline'
 begin
   require 'v8'
 rescue LoadError

bin/v8

@@ -2,7 +2,6 @@
 lib = File.expand_path(File.dirname(__FILE__) + '/../lib')
 $:.unshift(lib) if File.exists?(lib) unless $:.member?(lib)
 
-require 'readline'
 begin
   require 'v8'
 rescue LoadError

lib/v8/cli.rb

@@ -75,6 +75,7 @@ module V8
     end
 
     def self.repl(cxt, exename)
+      require 'readline'
       puts "help() for help. quit() to quit."
       puts "The Ruby Racer #{V8::VERSION}"
       puts "Vroom Vroom!"