Mark python 3.5 support deprecated (#849)

* Mark python 3.5 unsupported

Fixes https://github.com/esphome/issues/issues/831

* Update .travis.yml

* Update typing dep

setup.py

@@ -28,7 +28,7 @@ REQUIRES = [
     'paho-mqtt==1.4.0',
     'colorlog==4.0.2',
     'tornado==5.1.1',
-    'typing>=3.6.6;python_version<"3.5"',
+    'typing>=3.6.6;python_version<"3.6"',
     'protobuf==3.10.0',
     'tzlocal==2.0.0',
     'pytz==2019.3',