Allow for slim jars to be uploaded

[Bekreth]

Currently, in order to submit a job as a JAR file, it requires to user to package the jar with all of its dependencies which leads to JAR files starting a 40MB because they have to package Scala and Gatling in them. Given that these are consistent dependencies in every JAR file, we should allow for the config.yml to specify what versions of these people are using and merge them with the JAR that is uploaded to decrease the network load required to setup a job.