gem install bundle 安装失败

1. 在进行安装bundle时，会出现如下的错误。
   # gem install bundle
   ERROR: Could not find a valid gem ‘bundle’ (>= 0), here is why:
   Unable to download data from https://rubygems.org/ - Errno::ECONNRESET: Connection reset by peer - SSL_connect (https://rubygems.org/latest_specs.4.8.gz)

2. 这种情况，是被墙了。

3. 需要替换了，如下：
   # gem sources --remove https://rubygems.org/
   https://rubygems.org/ removed from sources
   # gem sources -a http://ruby.taobao.org/
   Error fetching http://ruby.taobao.org/:
   bad response Not Found 404 (http://ruby.taobao.org/specs.4.8.gz)
   # gem sources -a https://ruby.taobao.org/
   source https://ruby.taobao.org/ already present in the cache
   # gem sources -l
   CURRENT SOURCES
   https://ruby.taobao.org/
   # gem install bundle
   Fetching: bundler-1.10.6.gem (100%)
   Successfully installed bundler-1.10.6