clean proper directory for es6 build
clean proper directory for es6 build

luisgabriel/RxJS,ReactiveX/rxjs,gjungb/RxJS,jeremymwells/RxJS,ReactiveX/rxjs,jaawerth/RxJS-1,luisgabriel/RxJS,SekibOmazic/RxJS,robwormald/RxJS,martinsik/rxjs,adrianomelo/RxJSNext,martinsik/rxjs,Amirus/RxJS-1,QuinntyneBrown/RxJS,luisgabriel/RxJS,SangKa/RxJS-Docs-CN,martinsik/rxjs,jadbox/RxJS,SekibOmazic/RxJS,jayphelps/rxjs,Brocco/RxJS,kwonoj/RxJS,QuinntyneBrown/RxJS,benlesh/RxJS,elliotschi/rxjs,SangKa/RxJS-Docs-CN,jeremymwells/RxJS,gjungb/RxJS,staltz/RxJSNext,figueredo/RxJS,jinroh/RxJS,smaye81/RxJS,elliotschi/rxjs,gjungb/RxJS,adrianomelo/RxJSNext,smaye81/RxJS,robwormald/RxJS,jayphelps/rxjs,justinwoo/RxJS,adrianomelo/RxJS-1,elliotschi/rxjs,pselle/RxJS,jaawerth/RxJS-1,sitexa/RxJS,RxJS-CN/RxJS-Docs-CN,sitexa/RxJS,benlesh/RxJS,martinsik/rxjs,staltz/RxJSNext,IgorMinar/RxJS,Drooids/RxJS,SangKa/RxJS-Docs-CN,mattpodwysocki/RxJS,SangKa/RxJS-Docs-CN,RxJS-CN/RxJS-Docs-CN,sitexa/RxJS,jaawerth/RxJS-1,Amirus/RxJS-1,justinwoo/RxJS,adrianomelo/RxJS-1,Brocco/RxJS,adrianomelo/RxJSNext,benlesh/RxJS,jadbox/RxJS,IgorMinar/RxJS,adrianomelo/RxJS-1,jayphelps/rxjs,gluck/RxJS,gluck/RxJS,gluck/RxJS,jinroh/RxJS,kwonoj/RxJS,Brocco/RxJS,RxJS-CN/RxJS-Docs-CN,Igorbek/rxjs5,gjungb/RxJS,Igorbek/rxjs5,mattpodwysocki/RxJS,figueredo/RxJS,staltz/RxJSNext,elliotschi/rxjs,robwormald/RxJS,jinroh/RxJS,ReactiveX/rxjs,pselle/RxJS,robwormald/RxJS,jayphelps/rxjs,gluck/RxJS,ReactiveX/RxJS,jadbox/RxJS,mattpodwysocki/RxJS,jinroh/RxJS,trxcllnt/RxJS,jaawerth/RxJS-1,Drooids/RxJS,justinwoo/RxJS,ReactiveX/rxjs,Igorbek/rxjs5,jayphelps/rxjs,Amirus/RxJS-1,pselle/RxJS,figueredo/RxJS,mattpodwysocki/RxJS,justinwoo/RxJS,Brocco/RxJS,trxcllnt/RxJS,adrianomelo/RxJSNext,ReactiveX/RxJS,Drooids/RxJS,kwonoj/RxJS,jeremymwells/RxJS,QuinntyneBrown/RxJS,ReactiveX/RxJS,trxcllnt/RxJS,kwonoj/RxJS,smaye81/RxJS,figueredo/RxJS,RxJS-CN/RxJS-Docs-CN,saneyuki/RxJS,Igorbek/rxjs5,staltz/RxJSNext,SekibOmazic/RxJS,sitexa/RxJS,luisgabriel/RxJS,jadbox/RxJS,ReactiveX/RxJS,saneyuki/RxJS,benlesh/RxJS,trxcllnt/RxJS,adrianomelo/RxJS-1