Fix OSX travis build
Fix OSX travis build

I guess there's some symlinks set up in the VMs so the paths don't
match. Make sure we use the real expanded paths.

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