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/api.py

@@ -10,6 +10,7 @@ from .core.kpi_specification import KPISpecification  # noqa
 from .core.execution_layer import ExecutionLayer  # noqa
 from .core.verifier import verify_workflow  # noqa
 from .core.verifier import VerifierError  # noqa
+from .execution import execute_layer, execute_workflow  # noqa
 
 from .data_sources.base_data_source_model import BaseDataSourceModel  # noqa
 from .data_sources.base_data_source import BaseDataSource  # noqa