`v0.6.0` tag is not parsed by Swift Package Manager

[bunnyhero]

When I add the URL https://github.com/mapbox/Fingertips as a dependency in Xcode, I cannot specify version 0.6.0 because the tag is not parsed by Xcode (it doesn't like the "v").

In this attached screenshot, notice how the highest version it shows is 0.4.0, because that's the highest tag it can parse.