Add TP-Link powerline and Archer C7 device trackers

[Onager]

Description:

Add two new TP-Link device trackers

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>

Example entry for configuration.yaml (if applicable):

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass

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

• Documentation added/updated in home-assistant.github.io No changes required.

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.

[homeassistant]

Hi @Onager,

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!

[rytilahti]

I suppose this has been mentioned earlier in other tplink related PRs, but I'd say it's time for someone to step up and create a library from the device specific communication and make this platform use that instead of having this all inside homeassistant's code base...

[amelchio]

Right, it has been mentioned/decreed before and a basic library actually already exists. So we should start using that.

@Onager I hope you are not put down by this, it's just that you picked a module already in bad shape for your first contribution.