Refactoring: Moves execution to a separate module.

Created by: stefanoborini

Two refactorings:

• moves the execute_workflow routine in a separate module
• changes the name and parameter ordering of layer execution.

force_bdss/core/tests/test_execution.py

@@ -16,7 +16,7 @@ from force_bdss.tests.probe_classes.factory_registry_plugin import \
     ProbeFactoryRegistryPlugin
 from force_bdss.tests.probe_classes.mco import ProbeMCOFactory
 
-from force_bdss.execution import execute_workflow, execute_layer, \
+from force_bdss.core.execution import execute_workflow, execute_layer, \
     _bind_data_values