Added bundler rvm support

See http://robots.thoughtbot.com/post/15346721484/use-bundlers-binstubs

Rakefile

@@ -11,6 +11,7 @@ task :install => [:submodules] do
   puts
 
   install_homebrew
+  install_rvm_binstubs
 
   # this has all the runcoms from this directory.
   file_operation(Dir.glob('git/*')) if want_to_install?('git configs (color, aliases)')
@@ -48,6 +49,16 @@ def run(cmd)
   `#{cmd}` unless ENV['DEBUG']
 end
 
+def install_rvm_binstubs
+  puts "======================================================"
+  puts "Installing RVM Bundler support. Never have to type"
+  puts "bundle exec again! Please use bundle --binstubs and RVM"
+  puts "will automatically use those bins after cd'ing into dir."
+  puts "======================================================"
+  run %{ chmod +x $rvm_path/hooks/after_cd_bundler }
+  puts
+end
+
 def install_homebrew
   puts "======================================================"
   puts "Installing Homebrew, the OSX package manager...If it's"