DS1307 real time clock component (#1441)

* initial support for DS1307 real time clock

* add simple test, make sync functions public

* cleanup lint

* add sync to/from rtc actions

* changes action names

* Update esphome/components/ds1307/ds1307.cpp

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

* Update esphome/components/ds1307/time.py

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

* fix suggested change

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

esphome/components/ds1307/time.py

@@ -0,0 +1,44 @@
+import esphome.config_validation as cv
+import esphome.codegen as cg
+from esphome import automation
+from esphome.components import i2c, time
+from esphome.const import CONF_ID
+
+
+CODEOWNERS = ['@badbadc0ffee']
+DEPENDENCIES = ['i2c']
+ds1307_ns = cg.esphome_ns.namespace('ds1307')
+DS1307Component = ds1307_ns.class_('DS1307Component', time.RealTimeClock, i2c.I2CDevice)
+WriteAction = ds1307_ns.class_('WriteAction', automation.Action)
+ReadAction = ds1307_ns.class_('ReadAction', automation.Action)
+
+
+CONFIG_SCHEMA = time.TIME_SCHEMA.extend({
+    cv.GenerateID(): cv.declare_id(DS1307Component),
+}).extend(i2c.i2c_device_schema(0x68))
+
+
+@automation.register_action('ds1307.write', WriteAction, cv.Schema({
+    cv.GenerateID(): cv.use_id(DS1307Component),
+}))
+def ds1307_write_to_code(config, action_id, template_arg, args):
+    var = cg.new_Pvariable(action_id, template_arg)
+    yield cg.register_parented(var, config[CONF_ID])
+    yield var
+
+
+@automation.register_action('ds1307.read', ReadAction, automation.maybe_simple_id({
+    cv.GenerateID(): cv.use_id(DS1307Component),
+}))
+def ds1307_read_to_code(config, action_id, template_arg, args):
+    var = cg.new_Pvariable(action_id, template_arg)
+    yield cg.register_parented(var, config[CONF_ID])
+    yield var
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+
+    yield cg.register_component(var, config)
+    yield i2c.register_i2c_device(var, config)
+    yield time.register_time(var, config)