Fix Go downloading issue

[andreydiveev]

$ make
mkdir -p go-1.11.5
rm -f go-1.11.5/bin/go
Downloading and unpacking Go 1.11.5.linux-amd64 to go-1.11.5
curl -s https://dl.google.com/go/go1.11.5.linux-amd64.tar.gz | tar xf - --strip-components=1 -C go-1.11.5
tar: Archive is compressed. Use -z option
tar: Error is not recoverable: exiting now
Makefile:29: recipe for target 'go-1.11.5/bin/go' failed
make: *** [go-1.11.5/bin/go] Error 2

[asergeyev]

Thanks for looking at this.

I'll merge but with note that root makefile is not for general use and will go away at some point. go get is desired source ops workflow