Beta version releases are incorrectly formatted

[billyjanitsch]

Hi, I just wanted to point out a slight mistake in how beta releases of this package are being published. They should be formatted as 1.0.0-beta.5 rather than 1.0.0-beta5. The latter is invalid semver and causes problems with version tooling (example) and with npm itself, e.g. #1122

[bvaughn]

It's too late to change this for the *beta releases but this has been fixed for the new rc releases, the latest of which is "1.0.0-rc.1". 😄

Cheers for pointing this out though @billyjanitsch!