Refine slot matchers; fix README version updater
In this release, I updated the slot/capabilities matcher criteria for HtmlUnitDriver:
- For Selenium 4, the
platformNamecapability will be considered. - For Selenium 3, the
browserVersion(a.k.a. -version) capability will be ignored.
I also updated the README file update patterns in build.gradle to match the Selenium 4 artifact names.