pip: add callback to inform caller that pip changed to master
pip: add callback to inform caller that pip changed to master

MariadeAnton/clappr,jfairley/clappr,wxmfront/clappr,Metrakit/clappr,clappr/clappr,shakin/clappr,flavioribeiro/clappr,kelonye/clappr,kelonye/clappr,tjenkinson/clappr,shakin/clappr,wxmfront/clappr,irongomme/clappr,jfairley/clappr,Pyrotoxin/clappr,dayvson/clappr,MariadeAnton/clappr,tjenkinson/clappr,Metrakit/clappr,clappr/clappr,dayvson/clappr,burakkp/clappr,MariadeAnton/clappr,burakkp/clappr,tarkanlar/clappr,Pyrotoxin/clappr,Peer5/clappr,tjenkinson/clappr,burakkp/clappr,jfairley/clappr,Metrakit/clappr,irongomme/clappr,clappr/clappr,tarkanlar/clappr,Peer5/clappr,flavioribeiro/clappr,kelonye/clappr,tarkanlar/clappr,dayvson/clappr,irongomme/clappr,wxmfront/clappr,leandromoreira/clappr,Pyrotoxin/clappr,Peer5/clappr,shakin/clappr,leandromoreira/clappr,leandromoreira/clappr,flavioribeiro/clappr