Changed README so MyGet shield shows pre-release package
Changed README so MyGet shield shows pre-release package

robgha01/cake,phrusher/cake,Sam13/cake,phenixdotnet/cake,gep13/cake,robgha01/cake,michael-wolfenden/cake,thomaslevesque/cake,patriksvensson/cake,michael-wolfenden/cake,mholo65/cake,daveaglick/cake,devlead/cake,patriksvensson/cake,vlesierse/cake,cake-build/cake,RehanSaeed/cake,RehanSaeed/cake,Julien-Mialon/cake,gep13/cake,phrusher/cake,thomaslevesque/cake,daveaglick/cake,ferventcoder/cake,devlead/cake,cake-build/cake,phenixdotnet/cake,ferventcoder/cake,mholo65/cake,vlesierse/cake,adamhathcock/cake,Sam13/cake,DixonD-git/cake,Julien-Mialon/cake,adamhathcock/cake