Implement worker

Closes #2 (closed)

tests/test_worker.py

@@ -9,5 +9,5 @@ def test_dummy():
 def test_import():
     """Import our newly created module, through importlib to avoid parsing issues"""
     worker = importlib.import_module("worker_generic_training_dataset.worker")
-    assert hasattr(worker, "Demo")
-    assert hasattr(worker.Demo, "process_element")
+    assert hasattr(worker, "DatasetExtractor")
+    assert hasattr(worker.DatasetExtractor, "process_element")