refactor(dom): simplify implementation of mockDOMSource.select() and .events()
refactor(dom): simplify implementation of mockDOMSource.select() and .events()

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