1.11.0

Adds support for the Go 1.11 release tree.

1.10.0

* add support for go1.10+

1.9.0

Make the tag versions match up with the Go versions we have support for. As of
this commit, we support up to 1.9.

1.0.0

The interface presented by this package seems like a good starting point, so
let's create a 1.0.0 release to denote the intent to not break backwards
compatibility.