README: Mention support "async" keyword from Python 3.5.
README: Mention support "async" keyword from Python 3.5.

emfcamp/micropython,cwyark/micropython,pozetroninc/micropython,trezor/micropython,PappaPeppar/micropython,emfcamp/micropython,mhoffma/micropython,Peetz0r/micropython-esp32,blazewicz/micropython,dinau/micropython,swegener/micropython,lowRISC/micropython,henriknelson/micropython,emfcamp/micropython,selste/micropython,jmarcelino/pycom-micropython,matthewelse/micropython,jmarcelino/pycom-micropython,SHA2017-badge/micropython-esp32,SHA2017-badge/micropython-esp32,trezor/micropython,deshipu/micropython,tobbad/micropython,SHA2017-badge/micropython-esp32,deshipu/micropython,hiway/micropython,pozetroninc/micropython,pozetroninc/micropython,AriZuu/micropython,bvernoux/micropython,adafruit/circuitpython,mhoffma/micropython,toolmacher/micropython,adafruit/circuitpython,hosaka/micropython,PappaPeppar/micropython,mpalomer/micropython,MrSurly/micropython-esp32,drrk/micropython,micropython/micropython-esp32,tralamazza/micropython,turbinenreiter/micropython,SHA2017-badge/micropython-esp32,tralamazza/micropython,mhoffma/micropython,Timmenem/micropython,SHA2017-badge/micropython-esp32,drrk/micropython,hiway/micropython,kerneltask/micropython,selste/micropython,TDAbboud/micropython,hiway/micropython,selste/micropython,mhoffma/micropython,bvernoux/micropython,MrSurly/micropython,tobbad/micropython,dxxb/micropython,mpalomer/micropython,MrSurly/micropython,cwyark/micropython,pfalcon/micropython,alex-march/micropython,PappaPeppar/micropython,pramasoul/micropython,infinnovation/micropython,dxxb/micropython,dmazzella/micropython,Timmenem/micropython,dinau/micropython,henriknelson/micropython,adafruit/circuitpython,hosaka/micropython,torwag/micropython,PappaPeppar/micropython,matthewelse/micropython,matthewelse/micropython,adafruit/circuitpython,trezor/micropython,selste/micropython,TDAbboud/micropython,praemdonck/micropython,hiway/micropython,emfcamp/micropython,jmarcelino/pycom-micropython,redbear/micropython,adafruit/circuitpython,redbear/micropython,infinnovation/micropython,Timmenem/micropython,pozetroninc/micropython,drrk/micropython,MrSurly/micropython-esp32,HenrikSolver/micropython,pramasoul/micropython,turbinenreiter/micropython,adafruit/micropython,dxxb/micropython,lowRISC/micropython,Peetz0r/micropython-esp32,MrSurly/micropython,pramasoul/micropython,emfcamp/micropython,infinnovation/micropython,adafruit/micropython,kerneltask/micropython,dinau/micropython,AriZuu/micropython,trezor/micropython,swegener/micropython,TDAbboud/micropython,oopy/micropython,tobbad/micropython,alex-march/micropython,ganshun666/micropython,ganshun666/micropython,HenrikSolver/micropython,mhoffma/micropython,pramasoul/micropython,tralamazza/micropython,cwyark/micropython,ryannathans/micropython,tuc-osg/micropython,oopy/micropython,MrSurly/micropython,toolmacher/micropython,infinnovation/micropython,tobbad/micropython,kerneltask/micropython,pramasoul/micropython,henriknelson/micropython,TDAbboud/micropython,jmarcelino/pycom-micropython,chrisdearman/micropython,micropython/micropython-esp32,oopy/micropython,redbear/micropython,toolmacher/micropython,blazewicz/micropython,drrk/micropython,micropython/micropython-esp32,blazewicz/micropython,cwyark/micropython,misterdanb/micropython,deshipu/micropython,torwag/micropython,adafruit/micropython,mpalomer/micropython,puuu/micropython,Peetz0r/micropython-esp32,deshipu/micropython,bvernoux/micropython,kerneltask/micropython,matthewelse/micropython,bvernoux/micropython,mpalomer/micropython,alex-march/micropython,tuc-osg/micropython,ganshun666/micropython,drrk/micropython,micropython/micropython-esp32,ganshun666/micropython,chrisdearman/micropython,misterdanb/micropython,swegener/micropython,praemdonck/micropython,bvernoux/micropython,alex-robbins/micropython,micropython/micropython-esp32,AriZuu/micropython,Peetz0r/micropython-esp32,hosaka/micropython,torwag/micropython,chrisdearman/micropython,adafruit/micropython,torwag/micropython,puuu/micropython,Timmenem/micropython,tuc-osg/micropython,tobbad/micropython,matthewelse/micropython,puuu/micropython,TDAbboud/micropython,pfalcon/micropython,puuu/micropython,tralamazza/micropython,turbinenreiter/micropython,adafruit/micropython,oopy/micropython,ganshun666/micropython,swegener/micropython,deshipu/micropython,misterdanb/micropython,dinau/micropython,pfalcon/micropython,pfalcon/micropython,AriZuu/micropython,dxxb/micropython,praemdonck/micropython,lowRISC/micropython,misterdanb/micropython,henriknelson/micropython,dmazzella/micropython,redbear/micropython,hosaka/micropython,dinau/micropython,matthewelse/micropython,alex-robbins/micropython,blazewicz/micropython,turbinenreiter/micropython,adafruit/circuitpython,puuu/micropython,MrSurly/micropython-esp32,Peetz0r/micropython-esp32,cwyark/micropython,blazewicz/micropython,ryannathans/micropython,henriknelson/micropython,tuc-osg/micropython,misterdanb/micropython,infinnovation/micropython,mpalomer/micropython,tuc-osg/micropython,ryannathans/micropython,alex-march/micropython,oopy/micropython,lowRISC/micropython,praemdonck/micropython,selste/micropython,alex-robbins/micropython,trezor/micropython,dmazzella/micropython,kerneltask/micropython,MrSurly/micropython-esp32,HenrikSolver/micropython,Timmenem/micropython,MrSurly/micropython,AriZuu/micropython,swegener/micropython,jmarcelino/pycom-micropython,hiway/micropython,dxxb/micropython,pozetroninc/micropython,turbinenreiter/micropython,MrSurly/micropython-esp32,pfalcon/micropython,toolmacher/micropython,torwag/micropython,chrisdearman/micropython,ryannathans/micropython,chrisdearman/micropython,dmazzella/micropython,praemdonck/micropython,hosaka/micropython,alex-robbins/micropython,redbear/micropython,alex-robbins/micropython,toolmacher/micropython,PappaPeppar/micropython,alex-march/micropython,ryannathans/micropython,lowRISC/micropython,HenrikSolver/micropython,HenrikSolver/micropython