Add Wake over Lan support for Panasonic Viera

[Tony763]

Description:

Pass a ip address of device to WOL. Without it will not work on my TV.

Tox didn't pass. Tried pylint homeassistant/components/media_player/panasonic_v iera.py and it say:
panasonic_viera.py:45:4: E0611: No name 'RemoteControl' in module 'pana sonic_viera' (no-name-in-module) and this part I didn't touch.

Related issue (if applicable): fixes #

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

Example entry for configuration.yaml (if applicable):

media_player:
  - platform: panasonic_viera
    host: "10.0.1.108"
    mac: "20:C6:EB:AB:8B:20"

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[dgomes]

Looks good