Merge branch 'master' into maintainer

package.json

@@ -15,9 +15,10 @@
   "author": "Ian Richardson <iantrich@gmail.com>",
   "license": "MIT",
   "dependencies": {
-    "custom-card-helpers": "^1.3.5",
+    "custom-card-helpers": "^1.3.9",
     "home-assistant-js-websocket": "^4.4.0",
-    "lit-element": "^2.2.1"
+    "lit-element": "^2.2.1",
+    "lit-html": "^1.1.2"
   },
   "devDependencies": {
     "@babel/core": "^7.6.4",
@@ -27,7 +28,9 @@
     "@typescript-eslint/parser": "^2.6.0",
     "eslint": "^6.6.0",
     "eslint-config-airbnb-base": "^14.0.0",
+    "eslint-config-prettier": "^6.5.0",
     "eslint-plugin-import": "^2.18.2",
+    "eslint-plugin-prettier": "^3.1.1",
     "prettier": "^1.18.2",
     "rollup": "^1.26.0",
     "rollup-plugin-babel": "^4.3.3",