resources-go/v2: gopkg.in restructuring

Makes a v2 branch that is served via gopkg.in as a stable
version of the v2 API.

V2 is the latest, so until any backwards incompatible changes,
aside from the README and import paths, developments should be mirrored
here as well.
Update README.md

Fixed Godoc Badge, and some description updates.
resources-go/dev: made development version branch

The main master version of the package will now be for unstable
development. API compatible backports of fixes should be possible.

This is currently incomplete (missing some url's and badges) and also
will be held in a separate branch for a grace period so that followers
can update their code.