Add custom holidays to workday sensor (#21718)

* Add custom holidays to workday sensor

* correcting copy/paste errors

* resolve block comment and add default

* resolve line too long

* fixed handling of no custom holidays

* hound fixes

* rerun Travis

* @fabaff requested changes

* spaces v tabs

* Fix validation

homeassistant/components/binary_sensor/workday.py

@@ -42,6 +42,7 @@
 CONF_WORKDAYS = 'workdays'
 CONF_EXCLUDES = 'excludes'
 CONF_OFFSET = 'days_offset'
+CONF_ADD_HOLIDAYS = 'add_holidays'
 
 # By default, Monday - Friday are workdays
 DEFAULT_WORKDAYS = ['mon', 'tue', 'wed', 'thu', 'fri']
@@ -59,6 +60,7 @@
     vol.Optional(CONF_PROVINCE): cv.string,
     vol.Optional(CONF_WORKDAYS, default=DEFAULT_WORKDAYS):
         vol.All(cv.ensure_list, [vol.In(ALLOWED_DAYS)]),
+    vol.Optional(CONF_ADD_HOLIDAYS): vol.All(cv.ensure_list, [cv.string]),
 })
 
 
@@ -72,6 +74,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
     workdays = config.get(CONF_WORKDAYS)
     excludes = config.get(CONF_EXCLUDES)
     days_offset = config.get(CONF_OFFSET)
+    add_holidays = config.get(CONF_ADD_HOLIDAYS)
 
     year = (get_date(datetime.today()) + timedelta(days=days_offset)).year
     obj_holidays = getattr(holidays, country)(years=year)
@@ -92,6 +95,12 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
                           province, country)
             return
 
+    # Add custom holidays
+    try:
+        obj_holidays.append(add_holidays)
+    except TypeError:
+        _LOGGER.debug("No custom holidays or invalid holidays")
+
     _LOGGER.debug("Found the following holidays for your configuration:")
     for date, name in sorted(obj_holidays.items()):
         _LOGGER.debug("%s %s", date, name)