Upgrade Hibernate Validator to 6.0.11.Final

• Announcement: http://in.relation.to/2018/07/18/hibernate-validator-6011-final-out/
• Release notes: https://hibernate.atlassian.net/browse/HV-1637?jql=project%20%3D%20HV%20AND%20fixVersion%20in%20(6.0.11.Final)%20ORDER%20BY%20updated

This version is about improving JDK 11 support and fixes a few bugs.