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>

tests/test1.yaml

@@ -1837,6 +1837,20 @@ time:
       then:
         - lambda: 'ESP_LOGD("main", "time");'
   - platform: gps
+    on_time:
+      seconds: 0
+      minutes: /15
+      then:
+        ds1307.write:
+          id: ds1307_time
+  - platform: ds1307
+    id: ds1307_time
+    on_time:
+      seconds: 0
+      then:
+          ds1307.read
+
+
 
 cover:
   - platform: template