Support serving of backend translations (#12453)

* Add view to support backend translation fetching

* Load backend translations from component json

* Translations for season sensor

* Scripts to merge and unpack Lokalise translations

* Fix copy paste error

* Serve post-lokalise translations to frontend

* Linting

* Auto-deploy translations with Travis

* Commit post-lokalise translation files

* Split logic into more helper functions

* Fall back to English for missing keys

* Move local translation copies to `.translations`

* Linting

* Initial tests

* Remove unnecessary file check

* Convert translation helper to async/await

* Convert translation helper tests to async/await

* Use set subtraction to find missing_components

* load_translation_files use component->file mapping

* Remove duplicated resources fetching

Get to take advantage of the slick Python 3.5 dict merging here.

* Switch to live project ID

homeassistant/util/json.py

@@ -32,13 +32,13 @@ def load_json(filename: str, default: Union[List, Dict] = _UNDEFINED) \
     return {} if default is _UNDEFINED else default
 
 
-def save_json(filename: str, config: Union[List, Dict]):
+def save_json(filename: str, data: Union[List, Dict]):
     """Save JSON data to a file.
 
     Returns True on success.
     """
     try:
-        data = json.dumps(config, sort_keys=True, indent=4)
+        data = json.dumps(data, sort_keys=True, indent=4)
         with open(filename, 'w', encoding='utf-8') as fdesc:
             fdesc.write(data)
             return True