Refactoring docker tasks, adding dockerWithRetry back in

Run gradle clean in ant clean

Adding missing dependencies on common scala

Remove CMD from Dockerfile since further specification is needed by the caller

More idiomatic usage of gradle to generate eclipse project files for all projects (root and cli stay for the moment)

Using the configured SSL certificate in tests

Prevent travis from running gradle assemble, as it is not expected by our current build

Higher verbosity for test logs to make spotting issues from logs alone possible

Idiomatic configuration of scala compilation using resources

Setting DOCKER_HOST to mainmachine to build there

Signed-off-by: Fatih Ulusoy <ulusoy@de.ibm.com>