Update enums.py
Update enums.py

Added lines:
    CTR_TICK20ns = 10      # added for USB-1808 series JTG 1/21/2020
    CTR_TICK200ns = 11      # added for USB-1808 series JTG 1/21/2020     
    CTR_TICK2000ns = 12      # added for USB-1808 series JTG 1/21/2020    
    CTR_TICK20000ns = 13      # added for USB-1808 series JTG 1/21/2020   
for tick size support of counters on the USB-1808 series.
mccdaq/mcculw