zha: Add remove service

[rcloran]

Description:

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.

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

• Documentation added/updated in home-assistant.github.io

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

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass
• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New 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:

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass
• Tests have been added to verify that the new code works.

[houndci-bot]

import 'entity' from line 15 shadowed by loop variable

[houndci-bot]

'homeassistant.util.async.run_coroutine_threadsafe' imported but unused

[rcloran]

This seems to successfully remove a device, however, if I try to re-add the device without restarting home assistant, it complains that the entity already exists:

INFO:homeassistant.core:Bus:Handling <Event service_executed[L]: service_call_id=548301917264-73>
INFO:homeassistant.core:Bus:Handling <Event state_changed[L]: entity_id=light.sengled_e11g13_03064cb3_1, old_state=<state light.sengled_e11g13_03064cb3_1=off; supported_features=33, friendly_name=Sengled @ 2018-01-15T15:54:19.771414-08:00>, new_state=None>

...

INFO:homeassistant.components.zha:Permitting joins for 60s
...
ERROR:homeassistant.core:Error doing job: Task exception was never retrieved
Traceback (most recent call last):
  File "/usr/lib/python3.5/asyncio/tasks.py", line 239, in _step
    result = coro.send(None)
  File "/home/russell/src/home-assistant/homeassistant/helpers/entity_component.py", line 399, in async_process_entity
    new_entity, self, update_before_add=update_before_add
  File "/home/russell/src/home-assistant/homeassistant/helpers/entity_component.py", line 237, in async_add_entity
    'Entity id already exists: {}'.format(entity.entity_id))
homeassistant.exceptions.HomeAssistantError: Entity id already exists: light.sengled_e11g13_03064cb3_1

Any tips on what I'm missing?

[dmulcahey]

#10835 (and the forum post it references) seems to indicate that this is a limitation of hass if I'm reading it correctly.

[balloob]

#11691 should help with the re-adding issue.

[rcloran]

Rebased on dev, and this now appears to work (including re-adding without restart). Thanks for adding a way to remove in core!

[tylerakraft]

Sounds good, thank you.