Activated the arec preprocessor

pipeline/preprocessors/__init__.py

@@ -1,10 +1,12 @@
 from .default import DefaultProcessor
+from .arec import ArecProcessor
 from .cattura import CatturaProcessor
 from .mediasite import MediasiteProcessor
 from ..daisy import Daisy
 from ..utils import get_section
 
 allPreprocessors = {'default': DefaultProcessor,
+                    'arec': ArecProcessor,
                     'cattura': CatturaProcessor,
                     'mediasite': MediasiteProcessor,
                     }