feature request

[maltegrosse]

Hey, great work - but some features I really need are missing:
SMS
https://www.freedesktop.org/software/ModemManager/api/latest/gdbus-org.freedesktop.ModemManager1.Sms.html

Location (Including GPS data)
https://www.freedesktop.org/software/ModemManager/api/latest/gdbus-org.freedesktop.ModemManager1.Modem.Location.html

and finally a possibility to watch the states:
https://www.freedesktop.org/software/ModemManager/api/latest/ModemManager-Flags-and-Enumerations.html#MMModemState

and I also realized that I need to change following line to get your code working:
https://github.com/parrotmac/go-modemmanager/blob/master/pkg/modem/manager.go#L176
to
err := bus.Call(callModemLocationGetLocation, 0).Store(resp)

[maltegrosse]

thank you for your initial work. i used the last week to create a golang modem manager wrapper which got the functionalities I need.
https://github.com/maltegrosse/go-modemmanager