Compile for Windows binaries

[amaster507 (Anthony Master)]

Dropping support for Windows and Mac

Hey folks, We have decided to drop Windows and Mac support from Dgraph’s official releases. It was a hard decision that we did not want to make over the years, but both of these platforms require engineering efforts to maintain while only being used by 1.6% of our user base. We did the calculations based on our anonymous telemetry. Windows constitutes 1% usage, and Mac constitutes about 0.6% usage. This change would also allow us to use advanced Linux techniques like punching file holes for be…