Add Bundler to the Smile Gem environment.

It's needed for a bunch of things.

Repositories/Smile/Gemfile

+source "https://rubygems.org"
+gem 'bundler'
+
 source "https://rubygems.pkg.github.com/smile-io" do
     gem "smile-cli", "0.6.7"
 end
-
-source "https://rubygems.org" do
-end