Use a shallow copy of Zulip's Django fork.
Use a shallow copy of Zulip's Django fork.

This will substantially improve the performance of running provision
on systems with a relatively slow network.

Fixes #704.

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