Leverage access and refresh tokens if available (#575)

* Leverage access and refresh tokens if available

* Update homeassistant.py

* Update homeassistant.py

* Update proxy.py

* Migrate HomeAssistant to new exception layout

* Fix build for 3.7

* Cleanups

* Fix style

* fix log strings

* Fix new style

* Fix travis build

* python 3.7

* next try

* fix

* fix lint

* Fix lint p2

* Add logging

* Fix logging

* fix access

* Fix spell

* fix return

* Fix runtime

* Add to hass config

hassio/const.py

@@ -50,7 +50,7 @@ CONTENT_TYPE_JSON = 'application/json'
 CONTENT_TYPE_TEXT = 'text/plain'
 CONTENT_TYPE_TAR = 'application/tar'
 HEADER_HA_ACCESS = 'x-ha-access'
-HEADER_TOKEN = 'X-HASSIO-KEY'
+HEADER_TOKEN = 'x-hassio-key'
 
 ENV_TOKEN = 'HASSIO_TOKEN'
 ENV_TIME = 'TZ'
@@ -174,6 +174,7 @@ ATTR_DEVICETREE = 'devicetree'
 ATTR_CPE = 'cpe'
 ATTR_BOARD = 'board'
 ATTR_HASSOS = 'hassos'
+ATTR_REFRESH_TOKEN = 'refresh_token'
 
 SERVICE_MQTT = 'mqtt'