You may run into probelms like this:
Building native extensions. This could take a while...
ERROR: Error installing maxmind_geoip2:
ERROR: Failed to build gem native extension.
current directory: /Users/leonardteo/.rvm/gems/ruby-2.1.6@artstation/gems/maxmind_geoip2-0.0.8/ext/maxmind_geoip2
/Users/leonardteo/.rvm/rubies/ruby-2.1.6/bin/ruby -r ./siteconf20161227-1647-1c4uejw.rb extconf.rb
checking for maxminddb.h... no