Add LiteJet (a lighting control system) component (#4125)

* Initial submission of LiteJet integration.

* Add LiteJet switch pressed automation trigger. (State changes are too slow to catch a press-release.)
Add LiteJet scene, replacing commented out code that treated these as lights.
Include LiteJet numbers in the device state so that it is easy to lookup entity -> number.

* Fix missing global.

* Allow light's brightness to be set explicitly.

* Support optional 'ignore' key to ignore prefixes of loads, switches, and scenes that weren't configured for use in the LiteJet system.

* Fix lint errors and warnings.

* Cleanup header comments.
Default to not creating LiteJet switches as these are generally not useful.

* Lint fixes.

* Fixes from pull request feedback.

* Use hass.data instead of globals for data storage.

* Fix lint warnings.

homeassistant/components/automation/litejet.py

@@ -0,0 +1,41 @@
+"""
+Trigger an automation when a LiteJet switch is released.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/automation.litejet/
+"""
+import logging
+
+import voluptuous as vol
+
+from homeassistant.core import callback
+from homeassistant.const import CONF_PLATFORM
+import homeassistant.helpers.config_validation as cv
+
+DEPENDENCIES = ['litejet']
+
+_LOGGER = logging.getLogger(__name__)
+
+CONF_NUMBER = 'number'
+
+TRIGGER_SCHEMA = vol.Schema({
+    vol.Required(CONF_PLATFORM): 'litejet',
+    vol.Required(CONF_NUMBER): cv.positive_int
+})
+
+
+def async_trigger(hass, config, action):
+    """Listen for events based on configuration."""
+    number = config.get(CONF_NUMBER)
+
+    @callback
+    def call_action():
+        """Call action with right context."""
+        hass.async_run_job(action, {
+            'trigger': {
+                CONF_PLATFORM: 'litejet',
+                CONF_NUMBER: number
+            },
+        })
+
+    hass.data['litejet_system'].on_switch_released(number, call_action)