Bump master to 0.7.0

Looks like `master` is out-of-sync from the `v0.7.0` tag. This merges in the commit that updates the version.

Aside, I'm using a tool that depends on `git describe` to generate a work-in-progress gem for rapid iteration, and it currently returns `v0.6.1` since this commit is missing. `git describe` *should* return `v0.7.0` once this is merged.