Bump rake-compiler dependency
Bump rake-compiler dependency

It has some fixes for ruby 2.0.

webdev1001/byebug,yui-knk/byebug,miamiruby/byebug,guilherme/byebug,guilherme/byebug,ozydingo/byebug,scalp42/byebug,yui-knk/byebug,scalp42/byebug,davidmowrer/in_class_projects_t2,k0kubun/byebug,edward/byebug,saisai/byebug,phusion/byebug,k0kubun/byebug,ozydingo/byebug,deivid-rodriguez/byebug,deivid-rodriguez/byebug,davidmowrer/in_class_projects_t2,icebreaker/byebug,os97673/byebug,miamiruby/byebug,saisai/byebug,deivid-rodriguez/byebug,edward/byebug,webdev1001/byebug,guilherme/byebug,davidmowrer/in_class_projects_t2,phusion/byebug,os97673/byebug,icebreaker/byebug,yui-knk/byebug,k0kubun/byebug