We should respect the MINIKUBE_BUILD_IN_DOCKER param,
and also make the "docker inspect" output less verbose

And make the windows target repeatable, by leaving the
original output binary (copy instead of move) behind

But don't have any signing infrastructure yet

Need somewhere to store the private gpg keys.

But don't abort the build if gofmt is not installed.

golint wants "Json" to be properly spelled as "JSON"

Note that the sed syntax varies between GNU and BSD.

Since there is no git in the build container

The standard "fmt" target will also rewrite

Add return code, by checking for empty output

Also fix the broken fmt and reportcard ones:

Recursive variable 'SOURCE_DIRS' references itself (eventually).

Fix issue with exceeding shell command line length limits for certain setups.
https://git.buildroot.net/buildroot/tree/CHANGES?h=2018.05.x

making sure minikube is deleted before setup to avoid https://github.com/kubernetes/minikube/issues/4132

Not needed when using Go modules.

The default target (out/minikube) was replaced by "makedeploys",
that would always rebuild the deploy .yaml files from .template