当我尝试安装预编程器时，我只得到此错误...
C:\..mypath..\newsletter> gem install premailer
ERROR: Could not find a valid gem 'premailer' (>= 0), here is why:
Unable to download data from https://rubygems.org/ - SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (https://api.rubygems.org/latest_specs.4.8.gz)
那是我安装的ruby版本
ruby 2.1.5p273 (2014-11-13 revision 48405) [x64-mingw32]
任何人都知道如何修复该错误？