Fix reference to asyncio in README to the latest version
Fix reference to asyncio in README to the latest version

panda73111/aiohttp,AraHaanOrg/aiohttp,alexsdutton/aiohttp,alex-eri/aiohttp-1,vaskalas/aiohttp,KeepSafe/aiohttp,panda73111/aiohttp,iksteen/aiohttp,vaskalas/aiohttp,rutsky/aiohttp,rutsky/aiohttp,Insoleet/aiohttp,noodle-learns-programming/aiohttp,saghul/aiohttp,jettify/aiohttp,z2v/aiohttp,pathcl/aiohttp,decentfox/aiohttp,jashandeep-sohi/aiohttp,z2v/aiohttp,jettify/aiohttp,jashandeep-sohi/aiohttp,esaezgil/aiohttp,alex-eri/aiohttp-1,jashandeep-sohi/aiohttp,jojurajan/aiohttp,juliatem/aiohttp,Eyepea/aiohttp,alex-eri/aiohttp-1,singulared/aiohttp,arthurdarcet/aiohttp,juliatem/aiohttp,mind1master/aiohttp,jettify/aiohttp,danielnelson/aiohttp,morgan-del/aiohttp,rutsky/aiohttp,elastic-coders/aiohttp,decentfox/aiohttp,singulared/aiohttp,vasylbo/aiohttp,hellysmile/aiohttp,AraHaanOrg/aiohttp,AlexLisovoy/aiohttp,vedun/aiohttp,andyaguiar/aiohttp,moden-py/aiohttp,moden-py/aiohttp,saghul/aiohttp,arthurdarcet/aiohttp,KeepSafe/aiohttp,flying-sheep/aiohttp,mind1master/aiohttp,avanov/aiohttp,playpauseandstop/aiohttp,pfreixes/aiohttp,iksteen/aiohttp,hellysmile/aiohttp,panda73111/aiohttp,KeepSafe/aiohttp,noplay/aiohttp,elastic-coders/aiohttp,z2v/aiohttp,noplay/aiohttp,singulared/aiohttp,alunduil/aiohttp,vaskalas/aiohttp,Srogozins/aiohttp,alexsdutton/aiohttp,decentfox/aiohttp,mind1master/aiohttp,AlexLisovoy/aiohttp,elastic-coders/aiohttp,arthurdarcet/aiohttp,esaezgil/aiohttp,jojurajan/aiohttp,sterwill/aiohttp,esaezgil/aiohttp,moden-py/aiohttp,pfreixes/aiohttp