RandomLinesExample: fixed error and added unit tests
- RandomLinesExample: fixed error in case of exception: initialize result to false in the runExample method, switched to using the workflow factory instead of the workflow engine factory.
- RandomLinesExampleTest: use the Demonstration workflow type instead of Galaxy, added unit tests for a workflow returning false or throwing an exception.
- DemonstrationWorkflow and DemonstrationWorkflowEngine: moved custom functionality for the concatenate and random lines workflows from the DemonstrationWorkflowEngine.runWorkflow method to the DemonstrationWorkflow.run method.