v2.3.0: Merge pull request #26 from boylesoftware/issue-25
This release includes support for newer generate of Tomcat versions 9.0 and 8.5 and addresses internal tomcat API and protocols changes. This version of the authenticator works with Tomcat 9.0 versions 9.0.30 and higher and Tomcat 8.5 versions 8.5.50 and higher. Also, support for Tomcat 8.0 has been removed.