added test ETL for running tests

fractalis/data/etls/test/__init__.py

+__all__ = ['handler_test', 'etl_foo', 'etl_bar']

fractalis/data/etls/test/etl_foo.py

+from fractalis.data.etls.etl import ETL
+
+
+class FooETL(ETL):
+
+    _DATA_TYPE = 'foo'

fractalis/data/etls/test/handler_test.py

+from fractalis.data.etls.etlhandler import ETLHandler
+
+
+class TestHandler(ETLHandler):
+
+    _ETL = 'test'

fractalis/data/etls/transmart/handler_transmart.py

 from fractalis.data.etls.etlhandler import ETLHandler
 
 
-class HandlerTransmart(ETLHandler):
+class TransmartHandler(ETLHandler):
 
     _ETL = 'transmart'