help info for network test script missing --iperf3

The --help info for /usr/lib/plainbox-provider-checkbox/bin/network is missing the --iperf3 option.

/usr/lib/plainbox-provider-checkbox/bin/network --help
usage: network [-h] {test,info} ...

Network module

This script provides benchmarking and information for a specified network
interface.

Example NIC information usage:
network info -i eth0 --max-speed

For running iperf test:
network test -i eth0 -t iperf --target 192.168.0.1
NOTE: The iperf test requires an iperf server running on the same network
segment that the test machine is running on.

Configuration
=============

Configuration can be supplied in three different ways, with the following
priorities:

1- Command-line parameters (see above).
2- Environment variables (example will follow).
3- If run via checkbox/plainbox, /etc/xdg/checkbox-certification.conf
   can have the below-mentioned environment variables defined in the
   [environment] section. An example file is provided and can be simply
   modified with the correct values.

Environment variables
=====================
The variables are:
TEST_TARGET_IPERF

example config file
===================
[environment]
TEST_TARGET_IPERF = iperf-server.example.com

**NOTE**

positional arguments:
  {test,info}
    test Run network performance test
    info Gather network info

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