introduce a class to read shifts

dream/simulation/GUI/Shifts.py

+from copy import copy
+import json
+import time
+import random
+import operator
+
+from dream.simulation.GUI.Default import Simulation as DefaultSimulation
+
+
+class Simulation(DefaultSimulation):
+  def _preprocess(self, data):
+    """Preprocess data, reading shift spreadsheet"""
+    # TODO
+    return data
+
+  def run(self, data):
+    return DefaultSimulation.run(self._preprocess(data))