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

.travis.yml

@@ -1,6 +1,6 @@
 sudo: false
 language: python
-python: '3.5'
+python: '3.6'
 install: script/setup
 cache:
   directories:
@@ -15,8 +15,8 @@ matrix:
         - script/ci-custom.py
         - flake8 esphome
         - pylint esphome
-    - python: "3.5"
-      env: TARGET=Test3.5
+    - python: "3.6"
+      env: TARGET=Test3.6
       script:
         - esphome tests/test1.yaml compile
         - esphome tests/test2.yaml compile