Missing MacOs release for v21.03.0

[MichelDiz]

This will fix it

https://github.com/dgraph-io/Install-Dgraph/pull/21

Read this to know the reasons behind it

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…