Make sure TLS 1.2 is used to fetch from https://dot.net
Make sure TLS 1.2 is used to fetch from https://dot.net

https://github.com/dotnet/announcements/issues/77 for the change and
where I am stealing this change from.

jcouv/roslyn,KevinRansom/roslyn,bartdesmet/roslyn,dpoeschl/roslyn,weltkante/roslyn,gafter/roslyn,gafter/roslyn,ErikSchierboom/roslyn,diryboy/roslyn,AlekseyTs/roslyn,xasx/roslyn,aelij/roslyn,abock/roslyn,tannergooding/roslyn,physhi/roslyn,weltkante/roslyn,wvdd007/roslyn,reaction1989/roslyn,stephentoub/roslyn,davkean/roslyn,sharwell/roslyn,wvdd007/roslyn,weltkante/roslyn,KirillOsenkov/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,xasx/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,nguerrera/roslyn,stephentoub/roslyn,tannergooding/roslyn,jmarolf/roslyn,mavasani/roslyn,DustinCampbell/roslyn,jmarolf/roslyn,reaction1989/roslyn,diryboy/roslyn,AmadeusW/roslyn,brettfo/roslyn,tmat/roslyn,DustinCampbell/roslyn,nguerrera/roslyn,abock/roslyn,bartdesmet/roslyn,stephentoub/roslyn,CyrusNajmabadi/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,dotnet/roslyn,aelij/roslyn,shyamnamboodiripad/roslyn,jasonmalinowski/roslyn,genlu/roslyn,tmat/roslyn,VSadov/roslyn,bartdesmet/roslyn,cston/roslyn,genlu/roslyn,VSadov/roslyn,shyamnamboodiripad/roslyn,jcouv/roslyn,sharwell/roslyn,mavasani/roslyn,tannergooding/roslyn,davkean/roslyn,AmadeusW/roslyn,DustinCampbell/roslyn,AlekseyTs/roslyn,jmarolf/roslyn,MichalStrehovsky/roslyn,eriawan/roslyn,abock/roslyn,genlu/roslyn,jasonmalinowski/roslyn,KirillOsenkov/roslyn,mgoertz-msft/roslyn,panopticoncentral/roslyn,KevinRansom/roslyn,AmadeusW/roslyn,ErikSchierboom/roslyn,agocke/roslyn,VSadov/roslyn,diryboy/roslyn,MichalStrehovsky/roslyn,ErikSchierboom/roslyn,brettfo/roslyn,heejaechang/roslyn,swaroop-sridhar/roslyn,KevinRansom/roslyn,physhi/roslyn,KirillOsenkov/roslyn,eriawan/roslyn,nguerrera/roslyn,dotnet/roslyn,heejaechang/roslyn,agocke/roslyn,dpoeschl/roslyn,davkean/roslyn,CyrusNajmabadi/roslyn,dotnet/roslyn,panopticoncentral/roslyn,cston/roslyn,MichalStrehovsky/roslyn,panopticoncentral/roslyn,CyrusNajmabadi/roslyn,xasx/roslyn,wvdd007/roslyn,shyamnamboodiripad/roslyn,swaroop-sridhar/roslyn,gafter/roslyn,heejaechang/roslyn,reaction1989/roslyn,agocke/roslyn,dpoeschl/roslyn,jasonmalinowski/roslyn,mavasani/roslyn,tmat/roslyn,physhi/roslyn,AlekseyTs/roslyn,cston/roslyn,brettfo/roslyn,jcouv/roslyn,mgoertz-msft/roslyn,eriawan/roslyn,sharwell/roslyn,swaroop-sridhar/roslyn,aelij/roslyn,mgoertz-msft/roslyn