Update pre-release versions for current recommendations

According to Semver 2.0.0 section 11, the precedence for pre-releases should take the form of `-rc.1` instead of `-rc1`

The reason for this is that version precedence without the dots would be `1.0.0-rc10 < 1.0.0-rc2` but with the dots would be `1.0.0-rc.2 < 1.0.0-rc.10` which is intuitively more correct.