Binding to a specific source address

[shmul]

Hi,

currently there is no support for the client to specify the source address / interface name to use for the tests. I noticed the SpeedtestConfig struct contains an Interface field but it is unused. Do you plan on adding such a feature? This can be done either by referring to the Interface field or otherwise being able to provide the Dialer and/or Transport as part of the Config struct.
If you are interested, I'll be happy to implement and contribute such a change.

Cheers,
Shmul