Refactor periodic, now returns Stream<number>
Refactor periodic, now returns Stream<number>

feliciousx-open-source/cyclejs,feliciousx-open-source/cyclejs,usm4n/cyclejs,staltz/cycle,cyclejs/cyclejs,usm4n/cyclejs,cyclejs/cyclejs,feliciousx-open-source/cyclejs,cyclejs/cyclejs,staltz/cycle,ntilwalli/cyclejs,cyclejs/cyclejs,usm4n/cyclejs,ntilwalli/cyclejs,usm4n/cyclejs,feliciousx-open-source/cyclejs,ntilwalli/cyclejs,ntilwalli/cyclejs,cyclejs/cycle-core,cyclejs/cycle-core