accept 1.0 version number for set-release task

The `set-release` task didn't work with 1.0 version numbers. This PR fixes the misbehavior.
I'm not clear on why you're capturing the word "version" here? Also, it seems like it would be better (especially with your improvement to `safeReplace`) to have a regex that shows what it's expecting to replace rather than just `.*`. That's a minor point, though, given that we know we're replacing a `version` line.

You could also consider adding a `^` at the beginning.