Resolved unittest import problems.

tests/test_perf_tracking.py

@@ -17,7 +17,6 @@ import collections
 
 import unittest
 from nose_parameterized import parameterized
-import copy
 import random
 import datetime
 import pytz

tests/test_transforms.py

@@ -19,7 +19,6 @@ import pytz
 import numpy as np
 import pandas as pd
 
-from collections import deque
 from datetime import timedelta, datetime
 from unittest import TestCase