Create Custom Build image for customized kibana 6.4.3 source code

You're running docker build directly instead of using the Makefile. The Makefile does some rather complex logic https://github.com/elastic/kibana-docker/blob/907a9be2a38bea7e833e2f3d4557251780aaf6e4/Makefile#L67-L79. I'd recommend instead renaming your /kibana/target/*.tar.gz to match the expected files, or augmenting the kibana-docker/templates/Dockerfile.j2 to work with your existing archive naming.