chore(package.json): update angular2 beta.15
chore(package.json): update angular2 beta.15

budajeff/bingo,angular/angular2-seed,Nabysayna/angular2-seed,kastrulya/Ukraine,willyelm/angular2-seed,Nabysayna/angular2-seed,flai78/ng2FormTest,kastrulya/Ukraine,Manankishor/ComcastTechnicalScreening,Soolan/the-sherlock-project,Manankishor/ComcastTechnicalScreening,ogix/angular2-seed,angular/angular2-seed,icthis3t7/angular2-seed,AmyAmyZhu/ClownFish,sternof/seker,Soolan/the-sherlock-project,kfir124/angular2-seed,shruti-rao/Angular2Forms,abhivibhuti/SPCTool,willyelm/angular2-seed,Manankishor/ComcastTechnicalScreening,nadeeth/angular2-seed,sternof/seker,cpollard0/haloCoach,budajeff/bingo,Soolan/the-sherlock-project,budajeff/bingo,shumik-vladyslav/home-map,ziemowitprzebitkowski/tydzien-wykletych,flai78/ng2FormTest,dixso/angular2-seed,Arahir/hybrid-app,Arahir/hybrid-app,sternof/seker,shumik-vladyslav/snow,nadeeth/angular2-seed,megalucio/my-angular2-ecommerce-shop,jangroeneveld/portfolio,kfir124/angular2-seed,WoBinI/WoBinIGame,WoBinI/WoBinIGame,ziemowitprzebitkowski/tydzien-wykletych,WoBinI/WoBinIGame,abhivibhuti/SPCTool,shumik-vladyslav/snow,schaffe/Pathfinder,kastrulya/Ukraine,willyelm/angular2-seed,Soolan/the-sherlock-project,robertBrem/pokerui,AmyAmyZhu/ClownFish,cpollard0/haloCoach,dixso/angular2-seed,shumik-vladyslav/snow,schaffe/Pathfinder,cpollard0/haloCoach,Arahir/hybrid-app,shruti-rao/Angular2Forms,flai78/ng2FormTest,shumik-vladyslav/home-map,megalucio/my-angular2-ecommerce-shop,jangroeneveld/portfolio,AmyAmyZhu/ClownFish,icthis3t7/angular2-seed,dixso/angular2-seed,jangroeneveld/portfolio,schaffe/Pathfinder,ogix/angular2-seed,schaffe/Pathfinder,robertBrem/pokerui,icthis3t7/angular2-seed,shumik-vladyslav/home-map,robertBrem/pokerui,WoBinI/WoBinIGame,abhivibhuti/SPCTool,ogix/angular2-seed,megalucio/my-angular2-ecommerce-shop,Nabysayna/angular2-seed,kfir124/angular2-seed,angular/angular2-seed,nadeeth/angular2-seed,ziemowitprzebitkowski/tydzien-wykletych,shruti-rao/Angular2Forms