Usability and software architecture improvements

The initial goal of this beta release was to improve unit/integration tests and the architecture as a whole, to ensure it could be extended more easily in the future. As a side effect, we also managed to improve usability!

These are the outcomes of the last months of work:

• Tests are now completely independent from each other, using random test folders and Mongo databases
• Job parameters are fully validated using the Spring Batch API
• Job parameters can be conveniently read from a properties file, in addition to CLI arguments