Fix 'rake' and 'gem' detection on OS X.
Fix 'rake' and 'gem' detection on OS X.

antek-drzewiecki/passenger,cgvarela/passenger,gravitystorm/passenger,erikogan/passenger,jawj/passenger,clemensg/passenger,erikogan/passenger,fabiokung/passenger-debian,antek-drzewiecki/passenger,gravitystorm/passenger,kewaunited/passenger,phusion/passenger,antek-drzewiecki/passenger,gravitystorm/passenger,phusion/passenger,kewaunited/passenger,clemensg/passenger,pkmiec/passenger,clemensg/passenger,clemensg/passenger,cgvarela/passenger,pkmiec/passenger,antek-drzewiecki/passenger,fabiokung/passenger-debian,phusion/passenger,openSUSE/passenger,cgvarela/passenger,kewaunited/passenger,openSUSE/passenger,openSUSE/passenger,erikogan/passenger,cgvarela/passenger,openSUSE/passenger,gravitystorm/passenger,jawj/passenger,erikogan/passenger,bf4/passenger,pkmiec/passenger,pkmiec/passenger,kewaunited/passenger,clemensg/passenger,pkmiec/passenger,bf4/passenger,cgvarela/passenger,kewaunited/passenger,jawj/passenger,openSUSE/passenger,bf4/passenger,fabiokung/passenger-debian,clemensg/passenger,antek-drzewiecki/passenger,erikogan/passenger,kewaunited/passenger,clemensg/passenger,phusion/passenger,erikogan/passenger,pkmiec/passenger,jawj/passenger,jawj/passenger,kewaunited/passenger,openSUSE/passenger,clemensg/passenger,fabiokung/passenger-debian,antek-drzewiecki/passenger,antek-drzewiecki/passenger,antek-drzewiecki/passenger,cgvarela/passenger,cgvarela/passenger,pkmiec/passenger,bf4/passenger,phusion/passenger,phusion/passenger,cgvarela/passenger,fabiokung/passenger-debian,gravitystorm/passenger,fabiokung/passenger-debian,phusion/passenger,jawj/passenger,bf4/passenger,bf4/passenger,phusion/passenger,bf4/passenger,jawj/passenger,kewaunited/passenger,gravitystorm/passenger