removing redundant steps

Making sure that we are not creating too many intermediary images. Each
RUN command results in a new image during the build process. So if
possible consolidate steps where possible.
correcting CMD

Making sure we start a SSH Service and that we start the EAP instance
as the jbosseap user. We have to cd into the user home directory,
because uberfire creates a .index directory and it creates it in the
directory from which eap is started by default
enabling SSH to be able to SSH into the containers