Renamed MCO classes to consistency

Created by: stefanoborini

Changed the names from long to abbreviation to keep consistency of otherwise excessively long names.

Fixes #48 (closed)

force_bdss/core_plugins/dummy/dummy_dakota/dakota_bundle.py

 from traits.api import String
-from force_bdss.api import bundle_id, BaseMultiCriteriaOptimizerBundle
+from force_bdss.api import bundle_id, BaseMCOBundle
 
 from .dakota_communicator import DummyDakotaCommunicator
 from .dakota_model import DummyDakotaModel
 from .dakota_optimizer import DummyDakotaOptimizer
 
 
-class DummyDakotaBundle(BaseMultiCriteriaOptimizerBundle):
+class DummyDakotaBundle(BaseMCOBundle):
     id = String(bundle_id("enthought", "dummy_dakota"))
 
     name = "Dummy Dakota"