[Go1.9] New release to satify `dep` tool

[ChristianKniep]

I use your awesome library for years, but when switching to go1.9 dep seems to favour a released version instead of the master branch - somehow makes sense. :)

Can you release a new version, so that it can be picked up?

from README:

• API is stable. No major changes planned, maybe small improvements.

is there any need for versioning with an external tool then?
plus in few months there's Go release coming with it's own package versioning system, so I think we should be ready for that.
Is there any reason to keep this issue?