Java client libraries should be run against the EE

[garkler-zz]

Currently the "Java client for the CyberArk Conjur API" tests run only against the OSS.

Because of the configurable TLS change and because the client libraries especially Java are used by our customers we should add tests that should be run against the EE too.

[izgeri]

Adding some notes from discussions today:

• [ ] Update the Dockerfile.test to use openjdk:8 instead of java:8
• [ ] Update the conjur container in docker-compose.yml to use cyberark/conjur:latest
• [ ] Update the client container in docker-compose.yml to use cyberark/conjur-cli:5
• [ ] Update the Dockerfile.nginx to use nginx:1.13.6 (not critical, but couldn't hurt)

The java image update will hopefully help fix the broken build in this repo.

[szh]

This is implemented