[switch.wemo] Fix mW to kW conversion.

[lwis]

Description:

Conversion was wrong.

8954105 mW should convert to 8.954105 kW, not 8954.105 kW.

[mention-bot]

@lwis, thanks for your PR! By analyzing the history of the files in this pull request, we identified @pavoni, @balloob and @fabaff to be potential reviewers.

[houndci-bot]

line too long (82 > 79 characters)

[pavoni]

This was certainly wrong - but don't think this completely fixes it.

Hadn't finished digging - but I think wemo reports this in milliwatt minutes. So I think we probably also need to multiply by 60.

[lwis]

@pavoni I'm not sure I understand. That'll turn this calculation into 537 kW which is also very wrong.

[pavoni]

Sorry my description was wrong

    @property
    def today_energy_kwh(self):
        """Today total energy usage in kWh."""
        if self.insight_params:
            return convert(self.insight_params['todaymw'], float, 0.0) / (1000.0 * 1000.0 * 60)

[lwis]

@pavoni that looks much better, 0.14kW.