Goat (https://github.com/mediocregopher/goat), which isn't especially well known, does a lot of this in a more palatable way. I prefer using it when I don't need to edit/tweak my dependencies.
I also find gpm to be quite nice and resemble npm. (https://github.com/pote/gpm)
yeah, it's sad that go doesn't come with better dep and workspace built-in
This looks like almost exactly what I was thinking I'd do if I were to try to solve my issues with Go's way of doing things. Awesome.