Inserted spring in the binstubs

Now possible to run:
`bin/rails`
`bin/rspec`
`bin/spinach`
`bin/rake`

bin/rails

 #!/usr/bin/env ruby
+begin
+  load File.expand_path("../spring", __FILE__)
+rescue LoadError
+end
 APP_PATH = File.expand_path('../../config/application',  __FILE__)
 require_relative '../config/boot'
 require 'rails/commands'

bin/rake

 #!/usr/bin/env ruby
+begin
+  load File.expand_path("../spring", __FILE__)
+rescue LoadError
+end
 require_relative '../config/boot'
 require 'rake'
 Rake.application.run

bin/rspec

+#!/usr/bin/env ruby
+begin
+  load File.expand_path("../spring", __FILE__)
+rescue LoadError
+end
+require 'bundler/setup'
+load Gem.bin_path('rspec', 'rspec')

bin/spinach

+#!/usr/bin/env ruby
+begin
+  load File.expand_path("../spring", __FILE__)
+rescue LoadError
+end
+require 'bundler/setup'
+load Gem.bin_path('spinach', 'spinach')

bin/spring

+#!/usr/bin/env ruby
+
+# This file loads spring without using Bundler, in order to be fast
+# It gets overwritten when you run the `spring binstub` command
+
+unless defined?(Spring)
+  require "rubygems"
+  require "bundler"
+
+  if match = Bundler.default_lockfile.read.match(/^GEM$.*?^    spring \((.*?)\)$.*?^$/m)
+    ENV["GEM_PATH"] = ([Bundler.bundle_path.to_s] + Gem.path).join(File::PATH_SEPARATOR)
+    ENV["GEM_HOME"] = ""
+    Gem.paths = ENV
+
+    gem "spring", match[1]
+    require "spring/binstub"
+  end
+end