add the enumeration for the runway assignments

aman/config/RunwaySequencing.py

@@ -1,7 +1,13 @@
 #!/usr/bin/env python
 
+from enum import Enum
+
 from aman.types.Runway import Runway
 
+class RunwayAssignmentType(Enum):
+    AircraftType = 1
+    GateAssignment = 2
+
 class RunwaySequencing:
     def __init__(self, runway : Runway):
         self.Runway = runway