Fix #19 Python 3.8 import error

Python 3.8 ImportError: cannot import name 'clock' from 'time'

ethertoff/management/commands/index.py

@@ -5,7 +5,11 @@
 import os
 import json
 from urllib import error
-from time import clock
+try:
+    from time import clock
+except ImportError:
+    # Python >= 3.8
+    from time import perf_counter as clock
 
 # PyPi imports