1. Use --client since -c is deprecated now
2. The command (./kubectl version --client | grep -o 'GitVersion:"[^"]*"')
now returns:
GitVersion:"v1.4.0-alpha.1.784+ed3a29bd6aeb98-dirty"
so parse out the version better using sed
Related to #23708
This allows us to start building real dependencies into Makefile.
Leave old hack/* scripts in place but advise to use 'make'. There are a few
rules that call things like 'go run' or 'build/*' that I left as-is for now.