Add GitHub team and organisation authentication.
Add GitHub team and organisation authentication.

Fixes: #1473

ahmadassaf/zulip,susansls/zulip,KingxBanana/zulip,SmartPeople/zulip,susansls/zulip,peguin40/zulip,samatdav/zulip,verma-varsha/zulip,cosmicAsymmetry/zulip,shubhamdhama/zulip,brainwane/zulip,jainayush975/zulip,amyliu345/zulip,eeshangarg/zulip,Jianchun1/zulip,dattatreya303/zulip,zulip/zulip,aakash-cr7/zulip,reyha/zulip,Jianchun1/zulip,brockwhittaker/zulip,TigorC/zulip,sharmaeklavya2/zulip,isht3/zulip,niftynei/zulip,calvinleenyc/zulip,paxapy/zulip,susansls/zulip,tommyip/zulip,showell/zulip,joyhchen/zulip,vaidap/zulip,christi3k/zulip,dhcrzf/zulip,AZtheAsian/zulip,sup95/zulip,mahim97/zulip,KingxBanana/zulip,dawran6/zulip,Galexrt/zulip,sup95/zulip,krtkmj/zulip,synicalsyntax/zulip,blaze225/zulip,dattatreya303/zulip,umkay/zulip,vaidap/zulip,jainayush975/zulip,paxapy/zulip,zacps/zulip,vaidap/zulip,j831/zulip,zulip/zulip,zulip/zulip,blaze225/zulip,aakash-cr7/zulip,dawran6/zulip,hackerkid/zulip,krtkmj/zulip,JPJPJPOPOP/zulip,christi3k/zulip,peguin40/zulip,umkay/zulip,sonali0901/zulip,vabs22/zulip,calvinleenyc/zulip,Diptanshu8/zulip,sharmaeklavya2/zulip,isht3/zulip,jrowan/zulip,jackrzhang/zulip,grave-w-grave/zulip,jphilipsen05/zulip,Diptanshu8/zulip,paxapy/zulip,kou/zulip,tommyip/zulip,andersk/zulip,TigorC/zulip,cosmicAsymmetry/zulip,rht/zulip,zacps/zulip,sup95/zulip,SmartPeople/zulip,Galexrt/zulip,ahmadassaf/zulip,rishig/zulip,arpith/zulip,SmartPeople/zulip,shubhamdhama/zulip,tommyip/zulip,timabbott/zulip,amanharitsh123/zulip,umkay/zulip,aakash-cr7/zulip,arpith/zulip,peguin40/zulip,eeshangarg/zulip,niftynei/zulip,dawran6/zulip,samatdav/zulip,showell/zulip,jackrzhang/zulip,punchagan/zulip,Juanvulcano/zulip,rht/zulip,hackerkid/zulip,mohsenSy/zulip,ahmadassaf/zulip,shubhamdhama/zulip,TigorC/zulip,christi3k/zulip,Juanvulcano/zulip,dhcrzf/zulip,peguin40/zulip,krtkmj/zulip,niftynei/zulip,isht3/zulip,rht/zulip,verma-varsha/zulip,Diptanshu8/zulip,punchagan/zulip,samatdav/zulip,sup95/zulip,zulip/zulip,verma-varsha/zulip,jphilipsen05/zulip,Galexrt/zulip,brainwane/zulip,kou/zulip,andersk/zulip,grave-w-grave/zulip,andersk/zulip,timabbott/zulip,krtkmj/zulip,dattatreya303/zulip,mohsenSy/zulip,jainayush975/zulip,vikas-parashar/zulip,arpith/zulip,shubhamdhama/zulip,dhcrzf/zulip,dhcrzf/zulip,calvinleenyc/zulip,reyha/zulip,paxapy/zulip,timabbott/zulip,souravbadami/zulip,brainwane/zulip,amyliu345/zulip,calvinleenyc/zulip,JPJPJPOPOP/zulip,SmartPeople/zulip,isht3/zulip,showell/zulip,souravbadami/zulip,jackrzhang/zulip,eeshangarg/zulip,rishig/zulip,jrowan/zulip,vabs22/zulip,andersk/zulip,souravbadami/zulip,JPJPJPOPOP/zulip,jackrzhang/zulip,vabs22/zulip,kou/zulip,verma-varsha/zulip,TigorC/zulip,Diptanshu8/zulip,hackerkid/zulip,AZtheAsian/zulip,punchagan/zulip,AZtheAsian/zulip,verma-varsha/zulip,Galexrt/zulip,brockwhittaker/zulip,Juanvulcano/zulip,j831/zulip,tommyip/zulip,jackrzhang/zulip,mohsenSy/zulip,showell/zulip,rishig/zulip,punchagan/zulip,umkay/zulip,tommyip/zulip,blaze225/zulip,reyha/zulip,mohsenSy/zulip,sharmaeklavya2/zulip,vikas-parashar/zulip,zacps/zulip,jphilipsen05/zulip,Juanvulcano/zulip,samatdav/zulip,eeshangarg/zulip,joyhchen/zulip,cosmicAsymmetry/zulip,JPJPJPOPOP/zulip,vaidap/zulip,souravbadami/zulip,umkay/zulip,mahim97/zulip,susansls/zulip,mohsenSy/zulip,joyhchen/zulip,zulip/zulip,PhilSk/zulip,christi3k/zulip,brainwane/zulip,ryanbackman/zulip,timabbott/zulip,synicalsyntax/zulip,calvinleenyc/zulip,rishig/zulip,punchagan/zulip,sonali0901/zulip,jrowan/zulip,hackerkid/zulip,amyliu345/zulip,Diptanshu8/zulip,timabbott/zulip,reyha/zulip,showell/zulip,brockwhittaker/zulip,JPJPJPOPOP/zulip,umkay/zulip,paxapy/zulip,rht/zulip,samatdav/zulip,AZtheAsian/zulip,amanharitsh123/zulip,joyhchen/zulip,krtkmj/zulip,rht/zulip,sharmaeklavya2/zulip,verma-varsha/zulip,rht/zulip,dhcrzf/zulip,Galexrt/zulip,dawran6/zulip,zacps/zulip,punchagan/zulip,vaidap/zulip,eeshangarg/zulip,JPJPJPOPOP/zulip,calvinleenyc/zulip,hackerkid/zulip,tommyip/zulip,sup95/zulip,aakash-cr7/zulip,arpith/zulip,krtkmj/zulip,samatdav/zulip,niftynei/zulip,brockwhittaker/zulip,SmartPeople/zulip,kou/zulip,arpith/zulip,jphilipsen05/zulip,Juanvulcano/zulip,vabs22/zulip,jrowan/zulip,sonali0901/zulip,synicalsyntax/zulip,arpith/zulip,mahim97/zulip,umkay/zulip,Diptanshu8/zulip,ahmadassaf/zulip,mahim97/zulip,amyliu345/zulip,AZtheAsian/zulip,cosmicAsymmetry/zulip,KingxBanana/zulip,hackerkid/zulip,tommyip/zulip,reyha/zulip,rishig/zulip,Jianchun1/zulip,kou/zulip,ryanbackman/zulip,zacps/zulip,sonali0901/zulip,blaze225/zulip,ryanbackman/zulip,rishig/zulip,dattatreya303/zulip,brainwane/zulip,peguin40/zulip,hackerkid/zulip,kou/zulip,j831/zulip,amanharitsh123/zulip,reyha/zulip,jainayush975/zulip,shubhamdhama/zulip,Jianchun1/zulip,KingxBanana/zulip,niftynei/zulip,susansls/zulip,cosmicAsymmetry/zulip,joyhchen/zulip,j831/zulip,sonali0901/zulip,SmartPeople/zulip,jainayush975/zulip,timabbott/zulip,PhilSk/zulip,souravbadami/zulip,punchagan/zulip,synicalsyntax/zulip,ahmadassaf/zulip,PhilSk/zulip,showell/zulip,PhilSk/zulip,brockwhittaker/zulip,paxapy/zulip,ryanbackman/zulip,showell/zulip,KingxBanana/zulip,Galexrt/zulip,timabbott/zulip,vikas-parashar/zulip,brockwhittaker/zulip,grave-w-grave/zulip,jrowan/zulip,shubhamdhama/zulip,jackrzhang/zulip,andersk/zulip,TigorC/zulip,andersk/zulip,PhilSk/zulip,cosmicAsymmetry/zulip,rishig/zulip,ahmadassaf/zulip,vabs22/zulip,dhcrzf/zulip,zulip/zulip,isht3/zulip,jainayush975/zulip,isht3/zulip,vaidap/zulip,AZtheAsian/zulip,susansls/zulip,TigorC/zulip,mahim97/zulip,eeshangarg/zulip,blaze225/zulip,jackrzhang/zulip,KingxBanana/zulip,jphilipsen05/zulip,aakash-cr7/zulip,vikas-parashar/zulip,blaze225/zulip,Galexrt/zulip,amyliu345/zulip,eeshangarg/zulip,dattatreya303/zulip,amanharitsh123/zulip,shubhamdhama/zulip,niftynei/zulip,grave-w-grave/zulip,krtkmj/zulip,jphilipsen05/zulip,zacps/zulip,kou/zulip,grave-w-grave/zulip,sharmaeklavya2/zulip,ryanbackman/zulip,grave-w-grave/zulip,Juanvulcano/zulip,vikas-parashar/zulip,dawran6/zulip,Jianchun1/zulip,andersk/zulip,synicalsyntax/zulip,brainwane/zulip,sharmaeklavya2/zulip,j831/zulip,dattatreya303/zulip,sup95/zulip,synicalsyntax/zulip,joyhchen/zulip,amyliu345/zulip,synicalsyntax/zulip,mohsenSy/zulip,vikas-parashar/zulip,PhilSk/zulip,dhcrzf/zulip,peguin40/zulip,brainwane/zulip,Jianchun1/zulip,amanharitsh123/zulip,dawran6/zulip,christi3k/zulip,vabs22/zulip,ryanbackman/zulip,rht/zulip,mahim97/zulip,j831/zulip,aakash-cr7/zulip,jrowan/zulip,zulip/zulip,souravbadami/zulip,amanharitsh123/zulip,christi3k/zulip,ahmadassaf/zulip,sonali0901/zulip