Bump pywemo - fix for latest bridge firmware.

[pavoni]

Description:
Bump pywemo to fix problem with bridge in latest firmware.

pywemo/pywemo#62

Thanks to @markadr

Related issue (if applicable): fixes #

Pull request in home-assistant.github.io with documentation (if applicable): home-assistant/home-assistant.github.io#<home-assistant.github.io PR number goes here>

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[mention-bot]

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

[homeassistant]

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