some err : argparse's Inheriting parents

[DevineLiu]

the error make common_cli.py is method GetDeviceArguments() ‘s return object not be inherited

in the command line interface :
'''
--port_path PORT_PATH
USB port path integers (eg 1,2 or 2,1,1)
-s SERIAL, --serial SERIAL
Device serial to look for (host:port or USB serial)

'''
will not show

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[coveralls]

Coverage remained the same at 42.248% when pulling 47f3c2c on DevineLiu:master into 82bfd52 on google:master.

[DevineLiu]

I signed it!

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CLAs look good, thanks!