Upgrade pylint on python 3 to fix travis

esphome/config_validation.py

@@ -292,7 +292,7 @@ def time_period_str_colon(value):
     """Validate and transform time offset with format HH:MM[:SS]."""
     if isinstance(value, int):
         raise vol.Invalid('Make sure you wrap time values in quotes')
-    elif not isinstance(value, str):
+    if not isinstance(value, str):
         raise vol.Invalid(TIME_PERIOD_ERROR.format(value))
 
     try:
@@ -316,7 +316,7 @@ def time_period_str_unit(value):
     if isinstance(value, int):
         raise vol.Invalid("Don't know what '{0}' means as it has no time *unit*! Did you mean "
                           "'{0}s'?".format(value))
-    elif not isinstance(value, string_types):
+    if not isinstance(value, string_types):
         raise vol.Invalid("Expected string for time period with unit.")
 
     unit_to_kwarg = {

esphome/pins.py

@@ -290,7 +290,7 @@ def analog_pin(value):
         if 32 <= value <= 39:  # ADC1
             return value
         raise vol.Invalid(u"ESP32: Only pins 32 though 39 support ADC.")
-    elif CORE.is_esp8266:
+    if CORE.is_esp8266:
         if value == 17:  # A0
             return value
         raise vol.Invalid(u"ESP8266: Only pin A0 (17) supports ADC.")