remove superfluous imports

Former-commit-id: f1eef12a4575d9526bb285a8f404c0bbcc9d4bfe

models/examples/population/src/PopulationSimulation.py

@@ -6,7 +6,6 @@
 from statsmodels.tsa.holtwinters import Holt
 import pandas as pd
 import numpy as np
-import json
 
 
 def pop_sim(init_data, num_increments):

models/examples/water_demand/src/Water_Demand_Model.py

@@ -3,10 +3,6 @@
 # Distributed under the terms of the MIT License.
 
 
-import json
-import pandas as pd
-
-
 def Water_Demand_Simulation(countypop, rates):
 
     water = {}

outer_wrapper.py

@@ -9,7 +9,7 @@ from jsonschema import validate, ValidationError
 import time
 import glob
 from threading import Thread, Event
-from queue import Queue, Full, Empty
+from queue import Queue, Empty
 from abc import ABC, abstractmethod
 import os
 import sys