Nokogiri working install with latest XCode

fix-nokogiri

Homebrew has blacklisted libiconv so the majority of your help via google will not work now.  
Here's a way I figured out how to get nokogiri to compile if you made the mistake of upgrading your XCode version and you use RVM

1. Install packages via RVM
rvm pkg install libxslt
rvm pkg install libxml2
rvm pkg install iconv

2. Tell bundler how to build this by default
bundle config build.nokogiri --with-opt-dir=$rvm_home/usr

3. Bundle like a BOSS
bundle install