With this change, Druid will only support ZooKeeper 3.5.x and later.
In order to support Java 15 we need to switch to ZK 3.5.x client libraries and drop support for ZK 3.4.x
(see #10780 for the detailed reasons)
* remove ZooKeeper 3.4.x compatibility
* exclude additional ZK 3.5.x netty dependencies to ensure we use our version
* keep ZooKeeper version used for integration tests in sync with client library version
* remove the need to specify ZK version at runtime for docker
* add support to run integration tests with JDK 15
* build and run unit tests with Java 15 in travis
* move integration tests from ZooKeeper 3.4.x to 3.5.x
* run a subset of our integration tests with ZK 3.4 for backwards compatibility testing.
* remove need to build separate docker-base image
- use multi-stage build for the base image
- use openjdk base image instead of building our own JDK base
- workaround Debian not including MySQL by using MariaDB
- download mysql connector directly instead of using distro version
* fix incorrect openssl command failing on Debian
* keep mysql connector version in sync with pom version
* integration test refactor
* integration test refactor
* refactor integration test
* refactor integration test
* refactor integration test
* refactor integration test
* refactor integration test
* refactor integration test
* refactor integration test
* refactor integration test
* address comments
Xavier Léauté
Maytas Monsereenusorn