Add flow weak to createRenderer.js, fix potential bug
Add flow weak to createRenderer.js, fix potential bug

RafalFilipek/fela,risetechnologies/fela,derek-duncan/fela,derek-duncan/fela,risetechnologies/fela,risetechnologies/fela,rofrischmann/fela,RafalFilipek/fela,rofrischmann/fela,RafalFilipek/fela,as-com/alef,RafalFilipek/fela,RafalFilipek/fela,rofrischmann/fela,derek-duncan/fela,RafalFilipek/fela,derek-duncan/fela,derek-duncan/fela,as-com/alef,derek-duncan/fela,as-com/alef