安装compass失败
ERROR: Could not find a valid gem 'compass' (>= ), here is why:
Unable to download data from https://rubygems.org/ - SSL_connect retur
ned= errno= state=SSLv3 read server certificate B: certificate verify failed (
https://rubygems.org/latest_specs.4.8.gz)
百思不得其解，实在没有想到会是被墙了，然后找到了淘宝出的一个gem的镜像了，一试立马可用，大喜过望！
$ gem sources --remove https://rubygems.org/
$ gem sources -a https://ruby.taobao.org/
$ gem sources -l
*** CURRENT SOURCES *** https://ruby.taobao.org
# 请确保只有 ruby.taobao.org
$ gem install rails
然后再试一下gem install compass 就可以了
