Handle non-string values in JSON template renderer

[pnbruckner]

Description:

Using the SQL Sensor to extract a datetime value for a state (such as last_changed), and using value_template to convert that datetime to another format, was resulting in a TypeError being thrown by json.loads, indirectly called by async_render_with_possible_json_value in homeassistant.helpers.template. This error should be ignored so that the template can be rendered without value_json (just like what happens with a malformed JSON string.)

This change fixes that problem by catching TypeError in addition to ValueError.

Example error from log:

sql: Error on device update!
Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.5/site-packages/homeassistant/helpers/entity_platform.py", line 248, in _async_add_entity
    await entity.async_device_update(warning=False)
  File "/srv/homeassistant/lib/python3.5/site-packages/homeassistant/helpers/entity.py", line 349, in async_device_update
    await self.hass.async_add_executor_job(self.update)
  File "/usr/lib/python3.5/asyncio/futures.py", line 380, in __iter__
    yield self  # This tells Task to wait for completion.
  File "/usr/lib/python3.5/asyncio/tasks.py", line 304, in _wakeup
    future.result()
  File "/usr/lib/python3.5/asyncio/futures.py", line 293, in result
    raise self._exception
  File "/usr/lib/python3.5/concurrent/futures/thread.py", line 55, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/srv/homeassistant/lib/python3.5/site-packages/homeassistant/components/sensor/sql.py", line 160, in update
    data, None)
  File "/srv/homeassistant/lib/python3.5/site-packages/homeassistant/helpers/template.py", line 166, in async_render_with_possible_json_value
    variables['value_json'] = json.loads(value)
  File "/usr/lib/python3.5/json/__init__.py", line 312, in loads
    s.__class__.__name__))
TypeError: the JSON object must be str, not 'datetime'

Related issue (if applicable): none

Pull request in home-assistant.io with documentation (if applicable): none

Example entry for configuration.yaml (if applicable):

sensor:
  - platform: sql
    db_url: !secret db_url
    queries:
      - name: Get last_changed in local time
        query: "SELECT last_changed FROM states WHERE entity_id = 'domain.object_id' ORDER BY state_id DESC LIMIT 1;"
        column: last_changed
        value_template: "{{ strptime(value~'+0000', '%Y-%m-%d %H:%M:%S%z').astimezone(now().tzinfo) }}"

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 the code does not interact with devices:

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

[balloob]

Nice catch!