Updating dependencies
Merge remote-tracking branch 'filesystem/master'

* filesystem/master:
  Updating dependencies
Migrating files to make a module, without being a bundle

* Removing Symfony, making a separate module
* Adding new spec file, moving TaxModel to Tax
* Moving Interfaces out of the Entity namespace
* Adding Guardfile and updated composer file
* New method signatures, separating a Line from an Inventory item
* Adding specs class
* Implementation of InventoryItem, Tax, and their Interface counterparts
* Adjusting test cases
* Modifying previous test cases to the current refactor
Adding documentation and Event, to be used later