Add timestamp to json output

[oregonpillow]

In my example output:

[
  {
    "vendorid": 13651,
    "productid": 40961,
    "manufacturer": "PCsensor",
    "product": "TEMPerHUM",
    "busnum": 1,
    "devnum": 3,
    "devices": [
      "hidraw0",
      "hidraw1"
    ],
    "port": "1-10",
    "firmware": "TEMPerHUM_V4.1",
    "hex_firmware": "54454d50657248554d5f56342e310000",
    "hex_data": "802005ae17620000",
    "internal temperature": 14.54,
    "internal humidity": 59.86
  }
]

there is not timestamp, surely this is some key information that should be included within the output? A Linux epoch time for example.
Would be happy to submit PR for this,

[ccwienk]

hi @oregonpillow : I do not know why so many people seem to think I kind of adopted this project. I forked it some years back to add a patch that was useful for myself. I stopped using the usb-device years ago, and only veeeery infrequently check back w/ this repository.

will be happy to make anybody who is interested a collaborator.

edit: I just saw @eode seems to do work on this repository by now, so I guess that explains the traffic :-)

[oregonpillow]

Thanks @ccwienk i actually wanted to ask earlier what's the history of the split and which repo i should use. Just saw urwen#39 where @eode seems to have moved us over to here. I would be happy in collaborating on this project as a way of giving back a little.