Description of problem:
The arguments for gluster-mountbroker is missing help="< Some Text>" parameter wherever add_argument() is used due to which gluster-mountbroker help is missing  a brief description of what the argument does in the help of {add,setup,remove} as shown below:

# gluster-mountbroker remove --help
usage: gluster-mountbroker remove [-h] [--volume VOLUME] [--user USER]

optional arguments:
  -h, --help       show this help message and exit
  --volume VOLUME
  --user USER
# gluster-mountbroker add  --help
usage: gluster-mountbroker add [-h] volume user

positional arguments:
  volume
  user

optional arguments:
  -h, --help  show this help message and exit
# gluster-mountbroker setup  --help
usage: gluster-mountbroker setup [-h] mount_root group

positional arguments:
  mount_root
  group

optional arguments:
  -h, --help  show this help message and exit
# 


Version-Release number of selected component (if applicable):
Whatever is the current upstream version.

How reproducible:
constantly 

Steps to Reproduce:
1. Issue a # gluster-mountbroker {add|remove|setup} --help

Actual results:


Expected results:


Additional info: