Log Message:
Update ruby-bundler to 1.3.4.

## 1.3.4 (15 March 2103)

Bugfixes:

  - load YAML on Rubygems version that define module YAML
  - fix regression that broke --without on ruby 1.8.7

## 1.3.3

Features:

  - compatible with Rubygems 2.0.2 (higher and lower already work)
  - mention skipped groups in bundle install and bundle update output (@simi)
  - `gem` creates rake tasks for minitest (@coop) and rspec

Bugfixes:

  - require rbconfig for standalone mode
  - revert to working quoting of RUBYOPT on Windows (@ogra)