remove dependency on update-electron-app

package.json

@@ -21,8 +21,7 @@
     "electron-log": "^3.0.7",
     "esm": "3.*.*",
     "lit-html": "1.*.*",
-    "request": "2.*.*",
-    "update-electron-app": "^1.5.0"
+    "request": "2.*.*"
   },
   "devDependencies": {
     "electron": "4.*.*",