Refactored constructors and made WorkflowController a singleton.
Add calls to WorkflowController.getInstance() where necessary
Fixed broken test.
Removed unnecessary call to WorkflowModel.getInstance()
Merge branch 'dev-gradle' into refactor-workflow
Added Javadoc comment to WorkflowController.getInstance()
Merge branch 'refactor-workflow' of github.com:slash-slash-no-comment-WPI-cs3733/wpi-suite into dev-gradle