Add support for pry --gem
Add support for pry --gem

I am always doing pry -I./lib -r<gemname>.

printercu/pry,raeno/pry,bronzdoc/pry,jasnow/pry,tdg5/pry,sideci-sample/sideci-sample-pry,printercu/pry,shockone/pry,caporta/pry,scalixte-mdsol/pry,gfvcastro/pry,85x14/pry,ooohiroyukiooo/pry,bronzdoc/pry,richo/pry,shockone/pry,josue804/debunker,jasonm23/pry,shockone/pry,raeno/pry,caporta/pry,jasnow/pry,scalixte-mdsol/pry,tdg5/pry,pvdb/pry,sferik/pry,jasnow/pry,jasonm23/pry,nju520/pry,geoffreylitt/pry,raeno/pry,deivid-rodriguez/pry,icebreaker/pry,85x14/pry,icebreaker/pry,nju520/pry,sferik/pry,geoffreylitt/pry,josue804/debunker,ooohiroyukiooo/pry,ngpestelos/pry,tdg5/pry,caporta/pry,85x14/pry,ooohiroyukiooo/pry,gfvcastro/pry,nju520/pry,pvdb/pry,ngpestelos/pry,scalixte-mdsol/pry,jasonm23/pry